Refactor LessonPlan spec
Add spec for LessonPlan's class methods
Rename #resources -> #training_resources
Merge branch 'add_as_goal_to_trains' into add_lesson_plan_class_methods
Merge branch 'development' into add_lesson_plan_class_methods
Remove plan attribute from LessonPlan
Add factory to create a complex lesson plan
Remove spec related to the plan attributes and use the new factory for complex_lesson_plan
Remove validation related to plan attributes and implement #training_resources
Add spec for #goals
Implement #goals
Save relationship attributes to Trains model
Refactor factory for Contains relationship + Save lesson_plan_id to Contains relationship
Refactor spec and factories for Uses relationship and remove dependencies on LessonPlan's class method
Add lesson_plan_id to Uses relationship
Add lesson_plan_id to Requires relationship
Refactor Concept spec to use new factory for LessonPlan
Merge branch 'fix_models' into add_lesson_plan_class_methods
Add spec for #concepts and #requirements
Implement #concepts and #requirements