Use ES6 getters

Author: uds5501

app/routes/public/role-invites.js

@@ -10,8 +10,8 @@ export default Route.extend({
     this.loader
       .post('/role_invites/user', payload)
       .then(user => {
-        if (this.get('session.isAuthenticated')) {
-          if (this.get('authManager.currentUser.email') === user.email) {
+        if (this.session.isAuthenticated) {
+          if (this.authManager.currentUser.email === user.email) {
             this.loader
               .post('/role_invites/accept-invite', payload)
               .then(invite => {