added rspec tests
Merge branch 'master' of git://github.com/MarkUsProject/Markus
removed unused Assignment#submission_by(user) from project
corrected example description
fixed houndci complaints
Merge pull request #1862 from kubasub/master

RSpec tests
Travis CI
Remove debugger gem
migrated more rake tests to rspec tests
migrated tests for #valid_groupings and #invalid_groupings
Merge branch 'master' of git://github.com/MarkUsProject/Markus
fixed houndci complaints
refactored out unused Assignment#no_grouping_students_list method
Merge pull request #1871 from kubasub/master

RSpec test
Update travis.yml
Added debugger gem to development group
Merge pull request #1873 from david-yz-liu/travis-ci

Add Travis CI
Haskell highlighting
Fix up the brush
Merge pull request #1874 from david-yz-liu/haskell-syntax

Add Haskell syntax highlighting