adding the migration to fix has_submit issues
fixing titanic v.1 for the new submit
changing views to use the new has_submit derivation
new shcema with new has_submit split
titanic bootcamp doesn't have submit
new titanic has both content and written submit
using new submit for mh
statricks only has written submission
crime viz has both written and content submit
sql finance only has written submit
pandas intro don't have any submit
fixing admin view for the new has_submit
updating schema description in project
Merge pull request #894 from teamleada/tristan_has_submit_split

Tristan has submit split
Add company employees (company has_many employees)
Add relationships to company_employee and remove the company_id from users
Add companies relationship and clean up one-to-one relationships for users
Add some comments related to the user model
Add more comments and todos
Annotate models