chore(package): update eslint to version 3.8.0

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -15,7 +15,7 @@
     "chai": "^3.5.0",
     "chai-iterator": "^1.1.1",
     "chai-things": "^0.2.0",
-    "eslint": "^3.5.0",
+    "eslint": "^3.8.0",
     "gulp": "^3.9.1",
     "gulp-babel": "^6.1.2",
     "gulp-coveralls": "^0.1.4",