Move config to /etc/netbox/config (Fixes #54)

With this the configuration is moved to /etc/netbox/config and the
default reports directory is set to /etc/netbox/reports. This enables
the user to mount reports from a config map or persistent volume in
OpenShift.

docker-compose.yml

@@ -12,11 +12,11 @@ services:
         volumes:
         - ./startup_scripts:/opt/netbox/startup_scripts:ro
         - ./initializers:/opt/netbox/initializers:ro
-        - ./configuration:/etc/netbox:ro
+        - ./configuration:/etc/netbox/config:ro
         - netbox-nginx-config:/etc/netbox-nginx/
         - netbox-static-files:/opt/netbox/netbox/static
         - netbox-media-files:/opt/netbox/netbox/media
-        - netbox-report-files:/opt/netbox/netbox/reports
+        - netbox-report-files:/etc/netbox/reports:ro
     nginx:
         image: nginx:1.13-alpine
         command: nginx -g 'daemon off;' -c /etc/netbox-nginx/nginx.conf