code: def github_repo(github_repo, plugin_name):
      
      github_repo = _github_normalize(github_repo)
      repo_url = '%s%s' % (GH, github_repo)
  
      gr = GitRepo(repo_url, plugin_name)
      gr.init()
  
      return gr
docs: Returns a GitRepo from a github repository after either cloning or fetching
      (depending on whether it exists)
      @param github_repo: the github repository path, e.g. 'drupal/drupal/'
      @param plugin_name: the current plugin's name (for namespace purposes).