Update .jamie.yml and jamie gem version.
Fix .jamie.yml key.
Add minitest and fauxhai support.
Add support for PostgreSQL and MongoDB persistence modes.

This commit introduces new configuration attributes:

* `persist_mode`
* `persist_host`
* `persist_port`
* `persist_username`
* `persist_password`
* `persist_timeout`

The following attributes are deprecated with backward compatible
support:

* `mongodb_address`

See the README.md additions for more details.
Pin chef gem back at version 10 for now (used in unit tests).
Default nil persist_username & persist_password to empty string in conf.
Merge pull request #1 from bbg-cookbooks/postgres-support

Support :postgres Persist Plugin