Use Github API v3
Use UTC time to compare the current time versus the target branch time.
Merge the gatekeepers support
Document the new configuration option
Merge pull request #37 from nataren/gatekeepers

Document the new configuration option
Merge remote-tracking branch 'upstream/master' into use_github_api_v3
Merge pull request #38 from nataren/use_github_api_v3

Use specific github api version, namely v3.