Merge pull request #7 from afterwriting/greenkeeper/sinon-4.0.0

Update sinon to the latest version 🚀

[patch]

Author: ifrost

package.json

@@ -37,8 +37,9 @@
     "eslint": "^4.0.0",
     "istanbul": "^0.4.5",
     "jsdoc": "^3.4.3",
+    "mocha": "^3.4.2",
     "mocha": "^4.0.0",
-    "sinon": "^3.0.0",
+    "sinon": "^4.0.0",
     "webpack": "^3.0.0"
   }
 }