chore(package): update eslint to version 3.7.1

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -60,7 +60,7 @@
     "conventional-changelog-cli": "^1.2.0",
     "conventional-changelog-lint": "^1.0.0",
     "coveralls": "^2.11.13",
-    "eslint": "^3.6.0",
+    "eslint": "^3.7.1",
     "eslint-config-xo": "^0.15.4",
     "eslint-formatter-pretty": "^1.0.0",
     "eslint-plugin-ava": "^3.0.0",