[WIP] STI foreman provider (STI)

This creates the models to be used for creating the foreman configuration provider.



This feels like it needs a lot more.
Did I miss anything?
/cc @gmcculloug @brandondunne 
Would a case statement be cleaner?
```ruby
  val =
    case val
    when true then Open::SSL::VERIFY_PEER
    when false then Open::SSL::VERIFY_NONE
    else val
    end
```