Restore unittest-app to lp-cedarish

In creating our chef LP, unittest-app was removed from
lp-cedarish. This replaces it and restores the solum-pep.yaml
example so it works again.

Change-Id: If5d28f511d6528db055861235dd1ed117b6c5492
Merge "Restore unittest-app to lp-cedarish"