title: dateutil syntax error while deploying Flask Application
body: <p>I am trying to deploy a flask application (<a href="https://github.com/ihavemadefire/BestYearYet" rel="nofollow noreferrer">https://github.com/ihavemadefire/BestYearYet</a>) using Heroku. When I deploy it it crashes immediately.  I can't tell if the redirect is telling me there is an error in my code (It runs perfectly on a local browser port), an error in my virtual env or if there is an error in an external library.</p>
  
  <p>I have tried updating the appdirs and flask-dateutil libraries.  I have tried deploying from the Heroku git cli and from Github.  I checked my code to see if I missed something (but like I said, it runs fine locally)  I even tried rebooting.  I think this problem is beyond my experience level.</p>
  
  <p>Here are the relevant error logs from Heroku (greatly truncated):</p>
  
  <blockquote>
    <p>File
    "/app/.heroku/python/lib/python3.6/site-packages/alembic/script/base.py",
    line 7, in 
         from dateutil import tz    File "/app/.heroku/python/lib/python3.6/site-packages/dateutil/tz.py", line
    78
         <code>self._name</code>,
         ^</p>
  </blockquote>