Implement marking activities complete in activity detail page
Add icons to show activity's status in activity list page
Merge branch 'master' of github.com:lighthouse-labs/laser_shark into feature/63-complete-checkbox-button-for-marking-activities-complete
Merge branch 'feature/74-if-existing-user-bypass-get-started-page' of github.com:lighthouse-labs/laser_shark into feature/63-complete-checkbox-button-for-marking-activities-complete
move css for activity buttons to be nested inside section.activity-details, use newer syntax for built in validations, use default_value_for to set default value of completed_at time
Merge conflict
added git url to Activity Submissions
added validation for git url (required field)
added form to replace Mark as complete link
updated activity submission controller
changed git_url to github_url
linked up activity submission controller to new form, added url display once after submission
fixed submission form so it only displays for students
Added table for teachers to review students' progress
removed completion links from activity list view. fixed validation errors
added sorting by completed first to teacher's view
Merge branch 'feature/add-git-url-to-complete-activities' of https://github.com/marlonkenny/laser_shark into marlonkenny-feature/add-git-url-to-complete-activities

Conflicts:
	app/assets/stylesheets/activities.css.scss
	app/controllers/activities_controller.rb
	app/models/user.rb
	app/views/activities/show.html.slim
	db/schema.rb
merge corrections and ui changes to activity details page
Merge branch 'marlonkenny-feature/add-git-url-to-complete-activities'