Task to run all engine integration tests.
Use debugger gem when debugging
Upgrade to capybara 2.1.0

Was necessary to disable capybara-webkit for now.
Move Webmock setup into test_helper for clarity.
Add poltergeist and hook it up for JS tests

Had to fix some timing issues in some of the tests.  There are still a few with issues.
Fix changing answer JS tests.
Skip test for report-a-problem with JS enabled

This doesn't currently work due to a limitation in how Slimmer works.
Add comment explaining wait_until
Fix flakey test that was asserting float equality