Fix spelling mistake in README.md
Factor out the config portion for reuse.

- Create a small subpackage to allow the config to be loaded easily by
  a third party.
Add postgres support.

- As a consequence of postgres support 2 connections must be made to the
  database in order to create the database first, and then create the
  migrations table.
- Add more support to the interface for mundane queries since query
  parameters for insert etc are different in the pq driver.