fix testing syntax

Author: Kelly Selden

test/integration/index-test.js

@@ -349,7 +349,7 @@ describe(function() {
   });
 
   describe('Long running tests', function() {
-    this.timeout(240e3);
+    this.timeout(4 * 60e3);
 
     it('can update a custom blueprint for an ember app project', async function() {
       let finalStateFixturePath = 'test/fixtures/app/non-default-addon-blueprint/local/my-app';