chore(package): update eslint to version 3.1.1

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -77,7 +77,7 @@
     "babel-preset-min": "^0.1.15",
     "babel-register": "^6.9.0",
     "coveralls": "^2.11.11",
-    "eslint": "^3.1.0",
+    "eslint": "^3.1.1",
     "eslint-config-xo": "^0.15.2",
     "eslint-formatter-pretty": "^0.2.2",
     "eslint-plugin-ava": "^2.3.1",