chore(package): update eslint-plugin-standard to version 2.3.1

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -59,7 +59,7 @@
     "eslint-plugin-markdown": "^1.0.0-beta.3",
     "eslint-plugin-promise": "^3.5.0",
     "eslint-plugin-require-path-exists": "^1.1.5",
-    "eslint-plugin-standard": "^2.1.1",
+    "eslint-plugin-standard": "^2.3.1",
     "execa": "^0.6.3",
     "husky": "^0.13.2",
     "np": "^2.13.0",