Disable exam mode when teacher logs out.
Disable timeout for teachers & admins.
Test that exam mode is turned off when teachers log out.
Move disabled exam mode out of decorator and into the view
Refactor student testing tests to use multiple browsers for testing teacher enable/disable exams
Update expected queries to satisfy travis / sacrifice goat.
(goat) x 2
Merge pull request #2421 from dylanjbarth/2403-auto-disable-tests

Disable tests when teachers logout & disable timeout for teacher/admin accounts
Merge pull request #2428 from learningequality/nalanda-rct3

Nalanda rct3 into central-master