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

src/Routers/SessionsRouter.js

@@ -1,6 +1,6 @@
 
 import ClassesRouter from './ClassesRouter';
-import PromiseRouter from '../PromiseRouter';
+import Parse         from 'parse/node';
 import rest          from '../rest';
 import Auth          from '../Auth';
 import RestWrite     from '../RestWrite';
@@ -75,14 +75,14 @@ export class SessionsRouter extends ClassesRouter {
       expiresAt: Parse._encode(expiresAt)
     };
     const create = new RestWrite(config, masterAuth, '_Session', null, sessionData);
-    return create.execute().then(() => {
+    return create.execute().then(() => {
       // delete the session token, use the db to skip beforeSave
       return config.database.update('_User', {
         objectId: user.id
       }, {
         sessionToken: {__op: 'Delete'}
       });
-    }).then((res) => {
+    }).then(() => {
       return Promise.resolve({ response: sessionData });
     });
   }
@@ -94,7 +94,7 @@ export class SessionsRouter extends ClassesRouter {
     this.route('POST', '/sessions', req => { return this.handleCreate(req); });
     this.route('PUT', '/sessions/:objectId', req => { return this.handleUpdate(req); });
     this.route('DELETE', '/sessions/:objectId', req => { return this.handleDelete(req); });
-    this.route('POST', '/upgradeToRevocableSession', req => { return this.handleUpdateToRevocableSession(req); })
+    this.route('POST', '/upgradeToRevocableSession', req => { return this.handleUpdateToRevocableSession(req); })
   }
 }