Fix admin creation / editing of users

Closes #1741
Update a VCR cassette
Update to Rails 4.1

Other changes:

  * Remove xray-rails.
  * Updated RSpec, FactoryGirl.
  * I18n-JS updated to 3.0.0.rc5 (was 2.1.2).
  * JBuilder updated to 2.0.6 (was 1.5.2).
Make textarea style match that of input[type=text]
Fix labels on the "save scenario" form
Fix toggle links on the admin interface map
Merge pull request #1789 from quintel/rails-4.1

Update ETModel to Rails 4.1
Fix sidebar rendering when a sidebar item has no slides

No slides breaks since the view can't determine the "slide_key".