Remove Chakra check as they've resolve their 'vm' issue.

test/test.js

@@ -445,9 +445,6 @@
 
   // Add other realm values from the `vm` module.
   _.attempt(function() {
-    if (process.jsEngine === 'chakra') {
-      return;
-    }
     _.extend(_, require('vm').runInNewContext([
       '(function() {',
       ' var object = {',