Add add_user method to Project controller.
Suggested tests:
Add user to a project using an ADMIN user (should return 200 - OK)
Add user to a project using a user from any other level (should return 401 - Unauthorized)
Add user to a project that already has the same user (should return 500)
Add
add_usermethod toProjectcontroller.Suggested tests:
Add user to a project using an ADMIN user (should return 200 - OK)
Add user to a project using a user from any other level (should return 401 - Unauthorized)
Add user to a project that already has the same user (should return 500)