Merge branch 'development' into sample_data
Merge branch 'model/concept' into sample_data
modify seed yaml
Merge branch 'sample_data' into development
Remove Skill model
Add Requires relationship
Add relationship spec for Requires
Implement Requires relationship
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