Generate foreman sdk from api json

- Preserved old interface for methods: index, show, update, destroy
- Preserved plugin's interface
- You can choose to use the cache (files) or try the server first
- Ability to add more version definitions without having to change code

Change-Id: Ia03c48aeea493a9a90cbeeaeebbe478eaec1030c
Fixing the api generation

* Added 1.4.2 and 1.5.0 cache files (compatible with for 1.4.* 1.5.* foreman
  instances)
* Added missing create_* methods
* Improved the cache logic