title: Merge two remote branches in git
body: <h2>EDIT</h2>
  <p>Let me paraphrase, I would like to merge two git repositories with the same name, but different remote.</p>
  <p>That is, I have a repo_name hosted in git, under a branch name of repo_name_a and I added another branch to git under branch name : repo_name_b</p>
  <p>Now, to merge those, what can I do ?</p>