title: cannot import wsgi from gevent
body: <p>I am trying to run my heroku app locally so that I work on it when I don't have internet. I am able to run the app completely fine on the Heroku website after pushing it however I can't run it locally. When I run <code>heroku local</code> I get this error in particular:</p>
  
  <pre><code>11:17:19 web.1   |  Traceback (most recent call last):
  11:17:19 web.1   |    File "app.py", line 24, in &lt;module&gt;
  11:17:19 web.1   |      bottle.run(server='gevent', host='0.0.0.0', port=os.environ.get('PORT', 5000))
  11:17:19 web.1   |    File "/usr/local/lib/python2.7/site-packages/bottle.py", line 3127, in run
  11:17:19 web.1   |      server.run(app)
  11:17:19 web.1   |    File "/usr/local/lib/python2.7/site-packages/bottle.py", line 2907, in run
  11:17:19 web.1   |      from gevent import wsgi, pywsgi, local
  11:17:19 web.1   |  ImportError: cannot import name wsgi
  11:17:19 web.1   Exited with exit code 1
  </code></pre>
  
  <p>Please note I have downloaded gevent using <code>pip install gevent</code><br>
  Also I am on a mac version 10.13.5 in case that is relavent<br>
  Thanks</p>