Successfully handle 404 from Repository.issue()
Merge remote-tracking branch 'github/pr/49' into develop
test_iter_network_events and fix Repository.issue
Add notification fixture
test_iter_notifications
Add requires_auth to iter_notifications.

Add a safety check for the user in iter_pulls.
test_iter_pulls
test_iter_refs
test_iter_stargazers
test_iter_subscribers
test_iter_statuses
Add team fixture
test_iter_tags
test_iter_teams
test_mark_notifications
test_merge
test_milestone
Remove pubsubhubbub from Repository object

Add a note to the HISTORY and bump version to an alpha identifier
test_pull_request
README fixture