added comment model
remove the problem_comment and solution comment models
removed problem and solution comments from database
removed the comment concern and included votabale in comments
git change problem and solution model
comments is working
removed the last of the problem comments and solutions comments. fixed #156
Merge pull request #157 from codeflash/feature/polymorphic_comments

Feature/polymorphic comments
Update Gemfile.lock
Specify JS and CSS compressors
updated database seeds
updated the database
updated the tests
Move tests around to match the directory structure of Rails 4 tests (fix #161)
Made codeflash seed an admin.
updated seeds
fixed seeds
updated seeds
Updated Gemfiles
Merge branch 'master' into dev