Problem: travis osx does not support docker
Problem: travis osx does not support docker

Solution: do not check_zproject and check_zproto under osx

twhittock/zyre,hintjens/zyre,hintjens/zyre,twhittock/zyre,hintjens/zyre,twhittock/zyre,zeromq/zyre,zoobab/zyre,zeromq/zyre,hintjens/zyre,twhittock/zyre,zeromq/zyre,twhittock/zyre,zeromq/zyre,zoobab/zyre,zeromq/zyre,zeromq/zyre,twhittock/zyre,zoobab/zyre,hintjens/zyre,twhittock/zyre,hintjens/zyre,zeromq/zyre,hintjens/zyre,zoobab/zyre,zeromq/zyre,zoobab/zyre,zoobab/zyre,hintjens/zyre,zoobab/zyre,zoobab/zyre,twhittock/zyre