lomax: Adding the test_db ER overview diagram
lomax: Adding the test_db ER overview diagram

Signed-off-by: Simarpreet Singh <b16359d91242f1864a72d01c38610d02b4a514a3@opendns.com>

simar7/lemming,opendns/lemming,simar7/lemming,opendns/lemming,simar7/lemming,opendns/lemming