chore(package): update docdash to version 1.2.0

Closes #22

Author: greenkeeper[bot]

package.json

@@ -33,7 +33,7 @@
   "devDependencies": {
     "chai": "^4.0.2",
     "codecov": "^3.0.0",
-    "docdash": "^0.4.0",
+    "docdash": "^1.2.0",
     "eslint": "^5.0.0",
     "istanbul": "^0.4.5",
     "jsdoc": "^3.4.3",