Add Uses relationship
Add factories to create Uses relationship between LessonPlan and Resources
Add generic relationship spec for Uses + LessonPlan uses Resources relationship
Allow FactoryGril to add Resource to LessonPlan after creating the Uses relationship
Add TODO
Fix type in Uses spec: using 'users' instead of 'uses'
After saving the JSON, they keys are stored as string, so #resources need to use string, too
Merge branch 'model/lesson_plan' into model/uses
Convert LessonPlan's plan field to use String keys
Merge branch 'model/lesson_plan' into model/uses
Convert the Uses factory to use string keys when accessing LessonPlan's json field
Add test to verify that LessonPlan contains the Resource in a relationship
Create a standard relationship model for Uses relationship
Convert Resource spec to use string keys for json field
Convert ResourceValidator to use string keys for field data (json field)
Convert Resource factory to use string keys for field 'data'
Merge branch 'model/uses' into development
Merge branch 'model/resource' into development
Merge branch 'model/uses' into model/lesson_plan
Create a Uses relationship from LessonPlan to Resources upon creating the lesson plan