Can import exercises.
Highlight exercises on lessons page.
Filter lessons if they can be submitted.

For use with the `et` gem.
Wrote test to make sure that comments can be found on a users profile page
updated user show view for comments and controller to calculate count for # of comments on submissions
Include lesson type with API call.

Allows the `et` gem to differentiate between challenges and
exercises.
Document importing assignments in Readme
Merge pull request #148 from LaunchAcademy/add_exercises

Add exercises
Merge pull request #138 from LaunchAcademy/sd-comments-on-user-page

RFR: Added number of comments to profile page for users
Merge pull request #139 from LaunchAcademy/vr-your-comments-on-submissions

RFR -- Allow user to see how many comments they've produced on submissions
Add placeholder for the db/dumps directory.

Ignored directory that is used to store database dumps.
Add info on restoring a database snapshot.
Avoid extracting binary files from submissions.
Configure travis to install library dependencies.

Needed for the ruby-filemagic gem.
Merge pull request #149 from LaunchAcademy/invalid-byte-sequence

Invalid byte sequence