[#41157005] Exposed labellable resource to API

It is also resolve the following PT story:
Id: 42227565
Title: add create labellable spec in API
[#41157005] Added missing newline(s) at end of file(s)
[#41157005] Added spec from create label to the API

This is resolves the following PT story:
Id: 42227623
Title: add create labels spec in API
[#41157005] DRY the labellable related specs
Merge pull request #62 from ke4/41157005_expose_labels_in_the_api

41157005 expose labels in the api