add test case for low priority alerts
add test case for low priority alerts

br/apns4erl,scatterbrain/apns4erl,rmoorman/apns4erl,QBurstPoland/apns4erl,irccloud/apns4erl,why520crazy/apns4erl,arjan/apns4erl,br/apns4erl,comtihon/apns4erl,tomekowal/apns4erl,Soulforged/apns4erl,eleostech/apns4erl