title: Git merge open pull-request based on its ID
body: <p>Is it possible to merge open pull-request based on its id via command line? I'm able to list opened pull request based on curl 'https://api.github.com/search', which returns back open PRs with their IDs. I would like to merge some of PRs, ideally based on their IDs which are in response, but I couldn't find any way how to do it.</p>