Upgrade has a problem with the docker network name

[infosec-alchemist]

going from 0.3.6 to 0.3.7, the ugprade works.

But, then going from 0.3.7 to 0.3.9 fails because the docker containers are running in the "unfetter_default" network rather than the named network.

Look bringing down Unfetter from version 0.3.7 to 0.3.8 before continuing.