[broker] Rewrite adapter tests to match new interface
[broker] Rewrite adapter tests to match new interface

TheThingsNetwork/ttn,mgranberry/ttn,mgranberry/ttn,jvanmalder/ttn,TheThingsNetwork/ttn,LoRaWanSoFa/ttn,LoRaWanSoFa/ttn,TheThingsNetwork/ttn,jvanmalder/ttn,mgranberry/ttn,jvanmalder/ttn