removes unused capybara includes and updates database_cleaner version to avoid test crash
Merge pull request #26 from kevinburleigh75/update_database_cleaner

Updates database_cleaner version and removes unused capybara requires
fixed user sign in stuff, better dev and admin console with user search and sign in
Merge branch 'master' of github.com:openstax/tutor into jpslav_work_3
Merge pull request #30 from jpslav/jpslav_work_3

better sign in and out; admin and dev consoles with tabs, user search in each with sign-in capability