Peer Assessment Template/Styling Work:
* adding basic styling for rubric-based UI
* applying rubric-based UI styling to peer assessment
* adding oa-specific Sass extend partial
* basic template indentation cleanup
* adding initial JS for all collapsed/expanded UI to use
* refactoring small Sass bits

TIM-129
Exclude design.js from test execution
Merge pull request #67 from edx/talbs/styling-peerassessment

Peer Assessment Template/Styling Work