WSGI_PATH check multiple levels to find wsgi.py

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!