swap adventureworks for dvdrental

[smithjd]

replace functions associated with dvdrental in sp_docker_functions.R and sp_postgresql_functions.R

• sp_make_dvdrental_image
• sp_fetch_dvdrental_autodoc

[smithjd]

Follow logic in https://github.com/smithjd/sql-pet/blob/master/book-src/restore-adventureworks-postgres-on-docker.R except continue with convention of not using the standard Postgres port.