Add a new url subcommand to pgroll latest that returns a Postgres connection string with the latest version schema name set via the options query parameter in the connection string URL.

This would make it easier to integrate pgroll into application deployments and remove the need to manually construct a connection string from the output of pgroll latest schema.

Example usage

Assuming that the most recently started migration is 02_some_migration:

$ pgroll latest url

postgres://postgres:postgres@localhost:5432?options=-c%20search_path%3Dpublic_02_some_migration