EYETRACKER-2: Add AAF authentication
EYETRACKER-2: Use forked version of devise shibboleth authentication
EYETRACKER-2: Update Gemfile
EYETRACKER-2: Redirect unknown users to sign up page
EYETRACKER-2: Show email if logged in via AAF
EYETRACKER-2: Add cucumber tests and shibboleth authentication
EYETRACKER-2: Merge AAF changes into master