Phablytics

- Adds breadcrumbs to website

- Adds report setting: non_group_reviewer_acceptance_threshold
- Allows requiring a minimum number of acceptances by non-group reviewers for GroupReviewStatusReport

- Adds GroupReviewStatusReport
- adds web link for RevisionStatusReport and GroupsReviewStatusReport
- convert REPORTS config from dict to list

- update Maniphest open, closed statuses
- fix BugMetric namedtuple name

- Use accordion component to show/collapse bugs
- Fix Maniphest __str__ representation
- fix MANIPHEST_STATUSES_CLOSED vs MANIPHEST_STATUSES_OPE

- add metrics class and utils for generating metrics
- adds bugs report to metrics
- refactored get_maniphest_tasks functions to properly paginate
- moves markdown to requirements
- fixes an HTML revision status report formatting bug
- update README with release instructions