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