title: Rename merged branch name in bitbucket
body: <p>I'm new to Bitbucket. I've few merged branches in remote and I need to rename these with issue's name. Is there any way to rename these. While searching, I found a hack but I think deleting the branch and pushing it back is neither a good practice nor efficient since I've large number of branches that need to be rename.
  Any appreciation will be appreciated.Thank you</p>