Add create a workout spec
Add workout model, spec, route, controller
Add WorkoutExercise join table/model
Fix add workout spec
Accept nested attributes for workout_exercises
Add cocoon gem
Add associations to Exercise model
Fix model specs for associations
Add admin/workouts new & create actions
Add forms for creating workout
Remove workout validation on join table

Join records wouldn’t persist since workout wasn’t created when they
were being saved
Authorize admin for workouts controller
Merge pull request #13 from hchood/admin-creates-workout

Admin creates workout