Merge pull request #303 from pvginkel/environment-object-deletion

Fixed testing deletion of an environment object.

test/language/expressions/delete/11.4.1-4.a-5.js

@@ -10,7 +10,7 @@ info: >
     language provides no way to directly exercise [[Delete]], the tests are placed here.
 es5id: 11.4.1-4.a-5
 description: >
-    delete operator returns false when deleting the environment object
+    delete operator returns false when deleting the declaration of the environment object
     inside 'with'
 flags: [noStrict]
 includes: [runTestCase.js]