title: Deploy to heroku fails to deploy "no module dateutil.parser" when it's included in requirements.txt
body: <p>I'm a django newby and this is my first question posted to StackOverflow:</p>
  
  <p>I've successfully deployed a couple of apps to heroku over the past month but when I added a module fixed2csv that imports dateutil.parser, heroku fails to find the module even though it's in the requirements.txt file.</p>
  
  <p>Here's a snippet from heroku's deploy message...</p>
  
  <blockquote>
  <pre><code>   Downloading/unpacking python-dateutil==2.2 (from -r requirements.txt (line 20))
       Running setup.py (path:/tmp/pip_build_u20147/python-dateutil/setup.py) egg_info for
  </code></pre>
    
    <p>package python-dateutil</p>
  
  <pre><code>   Downloading/unpacking fixed2csv==0.2.3 (from -r requirements.txt (line 21))
       Downloading fixed2csv-0.2.3.tar.gz
       Running setup.py (path:/tmp/pip_build_u20147/fixed2csv/setup.py) egg_info for package
  </code></pre>
    
    <p>fixed2csv
               Traceback (most recent call last):
                 File "", line 17, in 
                 File "/tmp/pip_build_u20147/fixed2csv/setup.py", line 7, in 
                   import fixed2csv
                 File "fixed2csv.py", line 10, in 
                   import dateutil.parser
               ImportError: No module named dateutil.parser
               Complete output from command python setup.py egg_info:
               Traceback (most recent call last):</p>
  
  <pre><code>     File "&lt;string&gt;", line 17, in &lt;module&gt;
  
       File "/tmp/pip_build_u20147/fixed2csv/setup.py", line 7, in &lt;module&gt;
  
         import fixed2csv
  
       File "fixed2csv.py", line 10, in &lt;module&gt;
  
         import dateutil.parser
  
     ImportError: No module named dateutil.parser
  
     ----------------------------------------
     Cleaning up...
     Command python setup.py egg_info failed with error code 1 in /tmp/pip_build_u20147/fixed2csv
     Storing debug log for failure in /app/.pip/pip.log
  </code></pre>
    
    <p>!     Push rejected, failed to compile Python app</p>
  </blockquote>
  
  <p>Everything works fine in my virtualenv when I installed python-dateutil so I'm not sure where to go from here.</p>
  
  <p>Update:
  I worked around it by not using the module that required python-dateutil.  I would be interested to know how to get Heroku to recognize python-dateutil though because it's way nicer to use than messing around with strptime format strings.</p>