diff --git a/example/package-lock.json b/example/package-lock.json
index e86f61e..666332d 100644
--- a/example/package-lock.json
+++ b/example/package-lock.json
@@ -427,15 +427,15 @@
     "compression": {
       "version": "1.7.0",
       "resolved": "https://registry.npmjs.org/compression/-/compression-1.7.0.tgz",
-      "integrity": "sha1-AwyfGY8WQ6BX13anOOki2kNzAS0=",
+      "integrity": "sha512-EzpIPZX++rTQylMht3iaYigq2NNJbI/e9VaDzR8sLi8vgOCHpvLT93GuvsGYW2ANEd14Ax2nI1Ydi9L5ykGeig==",
       "requires": {
-        "accepts": "1.3.4",
+        "accepts": "~1.3.3",
         "bytes": "2.5.0",
-        "compressible": "2.0.11",
+        "compressible": "~2.0.10",
         "debug": "2.6.8",
-        "on-headers": "1.0.1",
+        "on-headers": "~1.0.1",
         "safe-buffer": "5.1.1",
-        "vary": "1.1.1"
+        "vary": "~1.1.1"
       }
     },
     "concat-map": {
@@ -552,7 +552,7 @@
     "debug": {
       "version": "2.6.8",
       "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.8.tgz",
-      "integrity": "sha1-5zFTHKLt4n0YgiJCfaF4IdaP9Pw=",
+      "integrity": "sha512-E22fsyWPt/lr4/UgQLt/pXqerGMDsanhbnmqIS3VAXuDi1v3IpiwXe2oncEIondHSBuPDWRoK/pMjlvi8FuOXQ==",
       "requires": {
         "ms": "2.0.0"
       }
@@ -774,42 +774,42 @@
     "express": {
       "version": "4.15.4",
       "resolved": "https://registry.npmjs.org/express/-/express-4.15.4.tgz",
-      "integrity": "sha1-Ay4iU0ic+PzgJma+yj0R7XotrtE=",
+      "integrity": "sha512-g48YBFQpZMDOGe/l9rOUinTcSBAtHVH17+0iFp/nwIP9Ik5thohP0feDe4M748aCOrlA7mC99mlUlbpxdZcq9w==",
       "requires": {
-        "accepts": "1.3.4",
+        "accepts": "~1.3.3",
         "array-flatten": "1.1.1",
         "content-disposition": "0.5.2",
-        "content-type": "1.0.2",
+        "content-type": "~1.0.2",
         "cookie": "0.3.1",
         "cookie-signature": "1.0.6",
         "debug": "2.6.8",
-        "depd": "1.1.1",
-        "encodeurl": "1.0.1",
-        "escape-html": "1.0.3",
-        "etag": "1.8.0",
-        "finalhandler": "1.0.4",
+        "depd": "~1.1.1",
+        "encodeurl": "~1.0.1",
+        "escape-html": "~1.0.3",
+        "etag": "~1.8.0",
+        "finalhandler": "~1.0.4",
         "fresh": "0.5.0",
         "merge-descriptors": "1.0.1",
-        "methods": "1.1.2",
-        "on-finished": "2.3.0",
-        "parseurl": "1.3.1",
+        "methods": "~1.1.2",
+        "on-finished": "~2.3.0",
+        "parseurl": "~1.3.1",
         "path-to-regexp": "0.1.7",
-        "proxy-addr": "1.1.5",
+        "proxy-addr": "~1.1.5",
         "qs": "6.5.0",
-        "range-parser": "1.2.0",
+        "range-parser": "~1.2.0",
         "send": "0.15.4",
         "serve-static": "1.12.4",
         "setprototypeof": "1.0.3",
-        "statuses": "1.3.1",
-        "type-is": "1.6.15",
+        "statuses": "~1.3.1",
+        "type-is": "~1.6.15",
         "utils-merge": "1.0.0",
-        "vary": "1.1.1"
+        "vary": "~1.1.1"
       },
       "dependencies": {
         "array-flatten": {
           "version": "1.1.1",
           "resolved": "https://registry.npmjs.org/array-flatten/-/array-flatten-1.1.1.tgz",
-          "integrity": "sha1-ml9pkFGx5wczKPKgCJaLZOopVdI="
+          "integrity": "sha512-PCVAQswWemu6UdxsDFFX/+gVeYqKAod3D3UVm91jHwynguOwAvYPhx8nNlM++NqRcK6CxxpUafjmhIdKiHibqg=="
         }
       }
     },
@@ -928,7 +928,8 @@
         },
         "ansi-regex": {
           "version": "2.1.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.1.1",
@@ -971,7 +972,8 @@
         },
         "balanced-match": {
           "version": "0.4.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "bcrypt-pbkdf": {
           "version": "1.0.1",
@@ -984,6 +986,7 @@
         "block-stream": {
           "version": "0.0.9",
           "bundled": true,
+          "optional": true,
           "requires": {
             "inherits": "2.0.3"
           }
@@ -991,6 +994,7 @@
         "boom": {
           "version": "2.10.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "hoek": "2.16.3"
           }
@@ -998,6 +1002,7 @@
         "brace-expansion": {
           "version": "1.1.7",
           "bundled": true,
+          "optional": true,
           "requires": {
             "balanced-match": "0.4.2",
             "concat-map": "0.0.1"
@@ -1005,7 +1010,8 @@
         },
         "buffer-shims": {
           "version": "1.0.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "caseless": {
           "version": "0.12.0",
@@ -1019,26 +1025,31 @@
         },
         "code-point-at": {
           "version": "1.1.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "combined-stream": {
           "version": "1.0.5",
           "bundled": true,
+          "optional": true,
           "requires": {
             "delayed-stream": "1.0.0"
           }
         },
         "concat-map": {
           "version": "0.0.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "cryptiles": {
           "version": "2.0.5",
@@ -1063,14 +1074,6 @@
             }
           }
         },
-        "debug": {
-          "version": "2.6.8",
-          "bundled": true,
-          "optional": true,
-          "requires": {
-            "ms": "2.0.0"
-          }
-        },
         "deep-extend": {
           "version": "0.4.2",
           "bundled": true,
@@ -1078,7 +1081,8 @@
         },
         "delayed-stream": {
           "version": "1.0.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "delegates": {
           "version": "1.0.0",
@@ -1100,7 +1104,8 @@
         },
         "extsprintf": {
           "version": "1.0.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "forever-agent": {
           "version": "0.6.1",
@@ -1119,11 +1124,13 @@
         },
         "fs.realpath": {
           "version": "1.0.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "fstream": {
           "version": "1.0.11",
           "bundled": true,
+          "optional": true,
           "requires": {
             "graceful-fs": "4.1.11",
             "inherits": "2.0.3",
@@ -1174,6 +1181,7 @@
         "glob": {
           "version": "7.1.2",
           "bundled": true,
+          "optional": true,
           "requires": {
             "fs.realpath": "1.0.0",
             "inflight": "1.0.6",
@@ -1185,7 +1193,8 @@
         },
         "graceful-fs": {
           "version": "4.1.11",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "har-schema": {
           "version": "1.0.5",
@@ -1219,7 +1228,8 @@
         },
         "hoek": {
           "version": "2.16.3",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "http-signature": {
           "version": "1.1.1",
@@ -1234,6 +1244,7 @@
         "inflight": {
           "version": "1.0.6",
           "bundled": true,
+          "optional": true,
           "requires": {
             "once": "1.4.0",
             "wrappy": "1.0.2"
@@ -1241,7 +1252,8 @@
         },
         "inherits": {
           "version": "2.0.3",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.4",
@@ -1251,6 +1263,7 @@
         "is-fullwidth-code-point": {
           "version": "1.0.0",
           "bundled": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "1.0.1"
           }
@@ -1262,7 +1275,8 @@
         },
         "isarray": {
           "version": "1.0.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "isstream": {
           "version": "0.1.2",
@@ -1325,11 +1339,13 @@
         },
         "mime-db": {
           "version": "1.27.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "mime-types": {
           "version": "2.1.15",
           "bundled": true,
+          "optional": true,
           "requires": {
             "mime-db": "1.27.0"
           }
@@ -1337,25 +1353,27 @@
         "minimatch": {
           "version": "3.0.4",
           "bundled": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "1.1.7"
           }
         },
         "minimist": {
           "version": "0.0.8",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "mkdirp": {
           "version": "0.5.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
         },
         "ms": {
           "version": "2.0.0",
-          "bundled": true,
-          "optional": true
+          "bundled": true
         },
         "node-pre-gyp": {
           "version": "0.6.36",
@@ -1395,7 +1413,8 @@
         },
         "number-is-nan": {
           "version": "1.0.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "oauth-sign": {
           "version": "0.8.2",
@@ -1410,6 +1429,7 @@
         "once": {
           "version": "1.4.0",
           "bundled": true,
+          "optional": true,
           "requires": {
             "wrappy": "1.0.2"
           }
@@ -1435,7 +1455,8 @@
         },
         "path-is-absolute": {
           "version": "1.0.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "performance-now": {
           "version": "0.2.0",
@@ -1444,7 +1465,8 @@
         },
         "process-nextick-args": {
           "version": "1.0.7",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "punycode": {
           "version": "1.4.1",
@@ -1477,6 +1499,7 @@
         "readable-stream": {
           "version": "2.2.9",
           "bundled": true,
+          "optional": true,
           "requires": {
             "buffer-shims": "1.0.0",
             "core-util-is": "1.0.2",
@@ -1519,13 +1542,15 @@
         "rimraf": {
           "version": "2.6.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "glob": "7.1.2"
           }
         },
         "safe-buffer": {
           "version": "5.0.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "semver": {
           "version": "5.3.0",
@@ -1573,22 +1598,24 @@
             }
           }
         },
-        "string_decoder": {
-          "version": "1.0.1",
-          "bundled": true,
-          "requires": {
-            "safe-buffer": "5.0.1"
-          }
-        },
         "string-width": {
           "version": "1.0.2",
           "bundled": true,
+          "optional": true,
           "requires": {
             "code-point-at": "1.1.0",
             "is-fullwidth-code-point": "1.0.0",
             "strip-ansi": "3.0.1"
           }
         },
+        "string_decoder": {
+          "version": "1.0.1",
+          "bundled": true,
+          "optional": true,
+          "requires": {
+            "safe-buffer": "5.0.1"
+          }
+        },
         "stringstream": {
           "version": "0.0.5",
           "bundled": true,
@@ -1597,6 +1624,7 @@
         "strip-ansi": {
           "version": "3.0.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "2.1.1"
           }
@@ -1609,6 +1637,7 @@
         "tar": {
           "version": "2.2.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "block-stream": "0.0.9",
             "fstream": "1.0.11",
@@ -1658,7 +1687,8 @@
         },
         "util-deprecate": {
           "version": "1.0.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "uuid": {
           "version": "3.0.1",
@@ -1683,7 +1713,8 @@
         },
         "wrappy": {
           "version": "1.0.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         }
       }
     },
@@ -2975,15 +3006,15 @@
     "serve-index": {
       "version": "1.9.0",
       "resolved": "https://registry.npmjs.org/serve-index/-/serve-index-1.9.0.tgz",
-      "integrity": "sha1-0rKA/FYNYW7oG0i/D6gqvtJIXOc=",
+      "integrity": "sha512-btXPFKITJiodQ9CaH6RrvVFMNAT8TcYz5DHpXdtY/7rpG5EXUV5Bw8Pu8GVUzCHlkEXOhEOLntXLzMhirMsBXw==",
       "requires": {
-        "accepts": "1.3.4",
+        "accepts": "~1.3.3",
         "batch": "0.6.1",
         "debug": "2.6.8",
-        "escape-html": "1.0.3",
-        "http-errors": "1.6.2",
-        "mime-types": "2.1.17",
-        "parseurl": "1.3.1"
+        "escape-html": "~1.0.3",
+        "http-errors": "~1.6.1",
+        "mime-types": "~2.1.15",
+        "parseurl": "~1.3.1"
       }
     },
     "serve-static": {
@@ -3143,14 +3174,6 @@
         "xtend": "4.0.1"
       }
     },
-    "string_decoder": {
-      "version": "1.0.3",
-      "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-1.0.3.tgz",
-      "integrity": "sha512-4AH6Z5fzNNBcH+6XDMfA/BTt87skxqJlO0lAh3Dker5zThcAxG6mKz+iGu308UKoPPQ8Dcqx/4JhujzltRa+hQ==",
-      "requires": {
-        "safe-buffer": "5.1.1"
-      }
-    },
     "string-width": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/string-width/-/string-width-1.0.2.tgz",
@@ -3161,6 +3184,14 @@
         "strip-ansi": "3.0.1"
       }
     },
+    "string_decoder": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-1.0.3.tgz",
+      "integrity": "sha512-4AH6Z5fzNNBcH+6XDMfA/BTt87skxqJlO0lAh3Dker5zThcAxG6mKz+iGu308UKoPPQ8Dcqx/4JhujzltRa+hQ==",
+      "requires": {
+        "safe-buffer": "5.1.1"
+      }
+    },
     "strip-ansi": {
       "version": "3.0.1",
       "resolved": "https://registry.npmjs.org/strip-ansi/-/strip-ansi-3.0.1.tgz",