Add support for credits

[calind]

[presslabs-bot]

This issue will be automatically closed on Tue, 17 Jan 2017 due to the lack of activity (comments or updates). Closed issues that remain inactive for a long period of time might also get automatically locked.

If you think this is an error or you want to keep the issue from being closed reply with a comment or apply the keep-open label to permanently disable auto-closing.

cc: @calind, @pdobrescu, @vtemian