title: Github: Define that only Beta branch can be merged into master branch?
body: <p>I want to set som restrictions or somehow define that only the beta branch, and poitentially any "hotfix" branch, can be merged into the master branch. Is this possible in GitHub?</p>
  
  <p>The reason is to avoid accidental pull requests from a feature or development branch into the master branch.
  Also, is it possible to have pull requests default to merge into a development branch, rather than default to merge into master?</p>