WSGI_PATH check multiple levels to find wsgi.py

[kmturley]

In addition would be great if your base image support multiple folder depths. wsgi.py is not always located one level deep. Especially if you have multiple django apps, you may want a command such as:

WSGI_PATH=`find /var/app | egrep 'wsgi.py'`

This would allow more projects based on this docker image, using a project structure such as:

/backend
    /polls
    /mysite
        wysgi.py
/frontend
    gulpfile.js
    package.json
    /src

Thanks!