Download repos list of a GitHub organization using Github API
# save it as a file named 'repos' and put in the github_stat/ directory.
curl https://api.github.com/orgs/NAL-i5K/repos?per_page=500 > repos
Usage:
python stat_github.py <startdate> <enddate>
ex: python stat_github.py 2017-10-1 2018-9-30
Output format: (file name: repos.stat)
repo1, <number of commit, number of file changed, number of insertion, number of deletion>
repo2, ...
repo3, ...