fixes quint tests and cucumber tests
adds check to see if exercise is saving to guarantee only 1 can be added
adds server validation for exercise uniqueness
merged in update_tests
adds protection for adding multiple exercises
trying to add tests but it's not working
updates error messages on comp exercise controller
updates compeitiion to competition exercises
adds creator to competitions
adds cucumber tests
clean up add exercises
adds more date validations for competitions
updates tests and fixes date validation for nil dates
Merge pull request #4 from CerebralStorm/add_exercise

Add exercise