Recent versions of the PG images require additional env vars

[zdavis]

More recent versions of PG image throw this error:

Error: Database is uninitialized and superuser password is not specified.
You must specify POSTGRES_PASSWORD to a non-empty value for the
superuser. For example, "-e POSTGRES_PASSWORD=password" on "docker run".
You may also use "POSTGRES_HOST_AUTH_METHOD=trust" to allow all
connections without a password. This is not recommended.
See PostgreSQL documentation about "trust":
https://www.postgresql.org/docs/current/auth-trust.html