count commits using Github API v4
count commits using Github API v4

The repo_info worker now uses Github API v4 to count commits
rather than making 3 Github REST API calls to calculate commit
count.

Signed-off-by: Parth Sharma <9e1953fae24da24239f2ad5c2daacfcdb4c74dcf@gmail.com>

OSSHealth/ghdata,OSSHealth/ghdata,OSSHealth/ghdata