Fix error in concept spec: extra 'end'
Fix Trains' spec: Use the correct factory and remove the tests with Skill model
Merge branch 'model/trains' into development
Merge branch 'model/concept' into development
Merge branch 'model/requires' into development
Merge branch 'development' into model/concept
Add tests and factory for Resources's class methods
Remove Skill model from Schema
Merge branch 'model/concept' into model/requires
Add lesson_plan_id to Requires relationship
Added lesson_plan_id to Requires relationship
Requires relationship need to have a lesson_plan_id to be valid