- Renamed ApiUrls.TeamsUpdateOrDelete method name to just "Team".  This
was done because the same Uri is also used to get a team, not just
updating and deleting.

- Fixed references pointing to method name that was changed.
- Added Get method to the Octokit/Clients/ITeamsClient interface.

- Implemented the aforementioned Get method in the
Octokit/Clients/TeamsClient class.

- Added test in Octokit.Tests/Clients/TeamsClientTests for the
aforementioned Get method.