title: Package requires a different Python: 2.7.17 not in '>=3.6.1' while setting up pre-commit
body: <p>I cloned a repository, installed pre-commit and was committing for <strong>the first time.</strong> 
  This is the time when pre-commit packages actually get installed and setup. I faced the following issue. </p>
  
  <pre><code>[INFO] Installing environment for https://github.com/asottile/seed-isort-config.
  [INFO] Once installed this environment will be reused.
  [INFO] This may take a few minutes...
  An unexpected error has occurred: CalledProcessError: command: ('/home/roopak/.cache/pre-commit/repokb2ckm/py_env-python2.7/bin/python', u'/home/roopak/.cache/pre-commit/repokb2ckm/py_env-python2.7/bin/pip', 'install', '.')
  return code: 1
  expected return code: 0
  stdout:
      Processing /home/roopak/.cache/pre-commit/repokb2ckm
  
  stderr:
      DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 is no longer maintained. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
      ERROR: Package 'seed-isort-config' requires a different Python: 2.7.17 not in '&gt;=3.6.1'
  </code></pre>