* provider/github: add GitHub labels resource
Provides a GitHub issue label resource.
This resource allows easy management of issue labels for an
organisation's repositories. A name, and a color can be set.
These attributes can be updated without creating a new resource.
* provider/github: add documentation for GitHub issue labels resource
Added the ability to set the "privacy" of a github_team resource so all teams won't automatically set to private.
* Added the privacy argument to github_team
* Refactored parameter validation to be general for any argument
* Updated testing
Paul Stack