Adds liniting into the workflow (#3082)

* initial linting of src

* fix indent to 2 spaces

* Removes unnecessary rules

* ignore spec folder for now

* Spec linting

* Fix spec indent

* nits

* nits

* no no-empty rule

spec/InMemoryCache.spec.js

@@ -15,7 +15,7 @@ describe('InMemoryCache', function() {
 
 
   function wait(sleep) {
-    return new Promise(function(resolve, reject) {
+    return new Promise(function(resolve) {
       setTimeout(resolve, sleep);
     })
   }