opennebula types and providers

continue working on onevnet type and provider
- add parameters and properties
- add getters and setters
- add spec tests

onecuster
- add parameters and properties
- add getters and setters
- add spec tests

onedatastores
- add parameters and properties
- add getters and setters
- add spec tests

add proper failing tests syntax
Merge branch 'typesproviders' of github.com:tuxmea/opennebula-puppet-module into typesproviders