Update composer.json to track ZF master
Update composer.json to track ZF master

2.1 is now in master so we can stop tracking the develop branch. Yay!
ZF-Commons/zfc-rbac,Ocramius/zfc-rbac,Orkin/zfc-rbac,Alexandre-T/zfc-rbac,bakura10/zfc-rbac,ZF-Commons/zfc-rbac,svycka/zfc-rbac,svycka/zfc-rbac,Ocramius/zfc-rbac,Alexandre-T/zfc-rbac,Orkin/zfc-rbac,bakura10/zfc-rbac