Include EsLint in grunt

ESlint is not turned on by default - as it gives us 500ish errors as of
the current state of the codebase, also, we should start linting
controllers (why arent we?)

EsLint contains angular best practices rules and will help us get V8
ready for Angular2 and to follow best practices, untill everything
passes we can turn it on and off during clean-up time

src/Umbraco.Web.UI.Client/package.json

@@ -22,6 +22,8 @@
   "dependencies": {},
   "devDependencies": {
     "bower": "^1.4.1",
+    "eslint": "^0.23.0",
+    "eslint-plugin-angular": "0.0.13",
     "grunt": "~0.4.0",
     "grunt-bower": "^0.19.0",
     "grunt-bower-install-simple": "^1.1.3",
@@ -32,6 +34,7 @@
     "grunt-contrib-jshint": "~0.2.0",
     "grunt-contrib-uglify": "~0.1.1",
     "grunt-contrib-watch": "~0.3.1",
+    "grunt-eslint": "^15.0.0",
     "grunt-html2js": "~0.1.0",
     "grunt-karma": "~0.5",
     "grunt-ngdocs": "~0.1.2",