Order lessons based on dependencies.
Optionally import lessons from local directory.

Allows for easier debugging without having to push curriculum
changes to a remote repository.
Merge pull request #99 from atsheehan/lesson_dependencies

Lesson dependencies
View list of teams as admin.
Prevent non-admin users from viewing team list.

Not sure if this is necessary since a user can still view single
teams and they can just change the URL to visit them.
Add admin links to navbar.
Merge pull request #100 from atsheehan/admin_views_teams

Admin views teams
Add test coverage for submission failures.

Respond to both web requests and API requests.
Remove unused submission view.

New submissions are submitted via the API using the `et` gem.
Use header tags consistently among pages.

The <h1> tag is used for the name of the application and <h2> tags
to describe the per-page contents.
Remove unnecessary padding.
Change styling for <ul> elements.

They look similar to the tables.
Merge pull request #101 from atsheehan/minor_tweaks

Minor tweaks
feature spec
feature complete
remove focus
submission doesn't need to be public
use double-quotes. more specific link checking
Merge pull request #103 from radavis/submission_download

Submission download
display number of comments on submissions index page