code: def get_default_repo(self):
          
          for repo in self.get_repos():
              if self.get_safe(repo, 'default') and self.getboolean(repo, 'default'):
                  return repo
          return False
docs: Go through all the repositories defined in the config file and search
          for a truthy value for the ``default`` key. If there isn't any return
          None.