The mariadb container currently doesn't persist it's database
anywhere. Map /var/lib/refstack/db to /var/lib/mysql in the
container.
We have /var/refstack and /var/lib/refstack with various things.
While we're here move everythign under /var/lib/refstack.
Also use 127.0.0.1 to ensure mysql doesn't try to connect over a
socket, but tcp (I think pymsql does anyway, but it's a little
clearer).
Change-Id: I5605eac2848a6b2222698bf20c707baa4442fcd5
a246df66b4