Add example Unit test to Toaster

Added an example unit test to the toaster application
which uses a live DataBroker. This is intended to show
how you can use the base test helpers to get access to
a live MD-SAL databroker.

Change-Id: I090b5806bf7bead086be3e85a5d42c64110aa8c2
Signed-off-by: Devin Avery <devin.avery@brocade.com>