add month_exp and week_exp for user
fix the bug of update_score_by_commits
fix the bug of 27
change 30.days.ago to at_beginning_of_month
Merge pull request #41 from caok/master

完成个人成长值
Merge pull request #42 from vincent178/master

READY: dry up the authentication of github api
project initialize from bay6
Merge pull request #43 from caok/master

project initialize from bay6
ongoing