Fix tests
Configure a default :from email parameter
Remove the Game::State error
Implement the contacting
Vertically center contact card
Migrate the database
Don't fade the contact modal

There was a glitch with the animation, so we just avoid it instead
Fix flash messages
Improve quiz browsing

* Quizzes have additional fields:
  - Cover photo
  - Time per question
  - Privacy
* Students can now play all quizzes in the database,
  and search them with full-text searching.

Concerns #124
Fixes #91
Fix tooltips for buttons
Temporarily hide contact card for mobile
Redesign School's quiz list
Refactor
Fix quiz edit form styling
Fix additional info component
Fix tooltips in button groups
Position dropdown carets better
Fix tooltip for correct answer indicator
Update spacer classes
Fix button positions in quiz edit view