Tests: Make tests run again

Summary:
QTip in addExamplesToInput (utils/answer-types.js:53) was
crashing several tests. This commit stubs out the jQuery
qtip function so that these tests pass again.

Test Plan:
 * run a server (`http-server -p 6060 .`)
 * run the tests ( http://localhost:6060/test/ )

Auditors: alex

Author: ariabuckles

test/index.html

@@ -42,6 +42,8 @@
             $.fn.tex.apply(this, arguments);
             return this;
         };
+        // Since we have some code that calls qtip executed by tests :(
+        $.fn.qtip = function() { return "fake qtip"; };
     </script>
     <script src="../local-only/underscore.js"></script>
     <script src="../local-only/kas.js"></script>