Bug 12478: Add the yaml mappings file

This should facilitate the modification of the mappings.
The yaml format is more readable than sql.

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jesse Weaver <jweaver@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>

Signed-off-by: Brendan Gallagher <brendan@bywatersolutions.com>

16.05.x