Update HISTORY to reflect what will happen
Update Gist iterators to use new paginated endpoints
Add integration test for Gist#iter_commits
Add integration test for GitHub#iter_forks
Remove obsolete test
Add Issue#iter_labels and integration test
Add etag parameter to Repository#milestone

- Add integration test for retrieving a milestone
Add etag parameter and Milestone#iter_labels integration test
Merge pull request #229 from sigmavirus24/new-pagination

New pagination