Add iteration lesson
Add blocks lesson
Add sandwich code lesson
Add classes lesson
Add open classes method
Add Dice Project
Add inheritance lesson
Add scoring project
Add modules method
Add scopes lesson
Add class methods lesson
Add message passing lesson
Add proxy class project
Add to_str lesson
Merge branch 'iteration'

* iteration:
  Add iteration lesson
Merge branch 'blocks'

* blocks:
  Add blocks lesson
Merge branch 'sandwich-code'

* sandwich-code:
  Add sandwich code lesson
Merge branch 'scoring-project'

* scoring-project:
  Add scoring project
Merge branch 'classes'

* classes:
  Add classes lesson
Merge branch 'open-classes'

* open-classes:
  Add open classes method