code: def update(self, folder, git_repository):
          
          # git clone
          try:
              self.clone(folder, git_repository)
          # git update if folder already exist
          except OSError:
              self.update_git_repository(folder, git_repository)
              self.pull(folder)
docs: Creates or updates theme folder according given git repository.
  
          :param git_repository: git url of the theme folder
          :param folder: path of the git managed theme folder