code: def create_tag_and_push(version):
      "Create a git tag for `version` and push it to origin."
      assert version not in tags()
      git('config', 'user.name', 'Travis CI on behalf of Austin Bingham')
      git('config', 'user.email', 'austin@sixty-north.com')
      git('config', 'core.sshCommand', 'ssh -i deploy_key')
      git(
          'remote', 'add', 'ssh-origin',
          'git@github.com:sixty-north/cosmic-ray.git'
      )
      git('tag', version)
  
      subprocess.check_call([
          'ssh-agent', 'sh', '-c',
          'chmod 0600 deploy_key && ' +
          'ssh-add deploy_key && ' +
          # 'git push ssh-origin HEAD:master &&'
          'git push ssh-origin --tags'
      ]f create_tag_and_push(version):
      "Create a git tag for `version` and push it to origin."
      assert version not in tags()
      git('config', 'user.name', 'Travis CI on behalf of Austin Bingham')
      git('config', 'user.email', 'austin@sixty-north.com')
      git('config', 'core.sshCommand', 'ssh -i deploy_key')
      git(
          'remote', 'add', 'ssh-origin',
          'git@github.com:sixty-north/cosmic-ray.git'
      )
      git('tag', version)
  
      subprocess.check_call([
          'ssh-agent', 'sh', '-c',
          'chmod 0600 deploy_key && ' +
          'ssh-add deploy_key && ' +
          # 'git push ssh-origin HEAD:master &&'
          'git push ssh-origin --tags'
      ])
docs: Create a git tag for `version` and push it to origin.