Create the following routes:

PUT /workout/{workout_id}
    This route will allow the user to update the change the name of the workout
    This route will allow the user to change the name of each exercise and the position/ordering of each exercise
    Ensure that positions are unique without the workout. So no two exercises within the workout should contain the same value
    This route will allow the user to delete any exercises
    This route will allow the user to add new exercises
    Any error messages should contain a user readable message
    Ensure logged in user is the owner of the workout

DELETE /workout/{workout_id}
    Ensure logged in user is owner of workout
    This route simply deletes the workout and all corresponding exercises
