ignores
put dockerfile back in shape

* carver/git doesn't exist, so use official debian image
* port expose is now done differently
* combine some commands for better docker performance
* make /var/dump/ for redis
* no need for sudo, looks like
* no need for 3rd party repo
* remove pointless copy of settings.py.example
* remove apt-get upgrade, we have a recent base image
* install skyline-start.sh for /usr/bin (tiny bit cleaner)
* clean up apt stuff at the end
update settings based on official example settings
fixes