Rename Repository#iter_hooks to Repository#hooks
Rename parameter for consistency
Experiment with the default ReadTheDocs theme
Rename Repository#iter_issues to Repository#issues
Rename Repository#iter_issue_events
Rename Repository#iter_keys

- Also test Repository#key while we are at it
Rename Repository#iter_labels
Add mention of Repository#iter_labels to HISTORY
Rename Repository#iter_languages
Rename Repository#iter_milestones
Rename Repository#iter_network_events
Update other tests to match the current style