chore(package): update gulp-eslint to version 5.0.0

Closes #14

Author: greenkeeper[bot]

package.json

@@ -26,7 +26,7 @@
     "eslint": "^3.10.2",
     "gulp": "^3.9.0",
     "gulp-babel": "^6.1.1",
-    "gulp-eslint": "^3.0.1",
+    "gulp-eslint": "^5.0.0",
     "gulp-mocha": "^3.0.1",
     "gulp-util": "^3.0.7",
     "gulp-watch": "^4.3.5",