features

[Hongyi23]

1. Unusually period of issues
2. None issue time
3. Unusually long time spent in a specific milestone.
4. Time spent in a milestone is unusually short.
5. large number of issues in a specific milestone.
6. small number of issues in a specific milestone.
7. large number of issues posted by a single user.
8. small number of issues posted by a single user.
9. issues involved users.
10. commits number in a specific time gap time?
11. commits by a single user.
12. number of pull request/branches.
13. number of time each label is used.
14. duration of issues.