chore(package): update coveralls to version 2.13.1

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -49,7 +49,7 @@
     "clinton": "^0.11.0",
     "conventional-changelog-cli": "^1.3.1",
     "conventional-changelog-lint": "^1.1.8",
-    "coveralls": "^2.13.0",
+    "coveralls": "^2.13.1",
     "cpy": "^5.0.0",
     "eslint": "^3.19.0",
     "eslint-config-standard": "^7.1.0",