While it is recommended to use `POSTGRES_PASSWORD`, I think it's good when we
can bring MSF up with minimum effort from scratch.
It shouldn't be an issue from the security point of view having the DB running
in a docker container with the 5432/tcp port available only to the MSF.
Adds a basic Dockerfile and docker-compose config. `docker-compose.yml`
adds a named volume for postgres so data should persist.
`$HOME/.msf4` will be mounted to `/root/.msf4` by default.
port 4444 is exposed by default
Basic Usage:
docker/bin/msfconsole
docker/bin/msfvenom