WIP: Docker enhancement

* reduces all needed containers into a single one
* simplifies initial startup command by adding docker-entrypoint.sh

docker-entrypoint.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+# Start all needed services inside the container!
+
+service nginx start
+service redis-server start
+celery -A konova worker --detach
+gunicorn konova.wsgi:application --bind 0.0.0.0:8000