Add contests table that will be an aggregate under an election
Created by: dbolson
@DSASanFrancisco/portal-members
Closes https://github.com/DSASanFrancisco/membership_api/issues/24
Created by: dbolson
@DSASanFrancisco/portal-members
Closes https://github.com/DSASanFrancisco/membership_api/issues/24