remove redis service from the image

Fix #149
If Hipache is not run as root, I don't know, I don't think so I would say. But, in this context, Hipache is run as root so it is ok.

However, Hipache drops root privileges to `www-data:www-data` as soon as ports are bound, and workers are still able to write into the log file even if it is owned by `root`. I think it is because the log file stream is open before workers downgrade privileges.