ExpertSenderEnum: added ::getTypes(), ::getOperators(), ::getOrders(), ::getModes() methods
Added Request\AddUserToList class – provides a clear interface to create user-list subscriptions (plus tests)
ExpertSenderTest: getParam() helper method + example configuration in params.json.dist
Merge pull request #6 from MonsterMediaGroup/AddUserToListRequest

Add user to list request value object