chore(package): update coveralls to version 2.11.13

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -28,7 +28,7 @@
     "babel-plugin-add-module-exports": "0.2.1",
     "babel-preset-es2015-node4": "2.1.0",
     "chai": "3.5.0",
-    "coveralls": "2.11.9",
+    "coveralls": "2.11.13",
     "cz-conventional-changelog": "1.1.6",
     "isparta": "4.0.0",
     "jsdoc-to-markdown": "1.3.6",