use `tutum/mysql:5.5` as baseimage for MySQL DBs
use `bitzesty/trade-tariff-backend:0.2` as image for backend

This image has the application bundled with new gems and `mysql-client`
Merge pull request #1 from bitzesty/remove-orchardups-mysql-baseimage

use `tutum/mysql:5.5` as baseimage for MySQL DBs