Merge pull request #29 from skunkwerks/hotfix/eunit-breakage

make eunit tests work again after adding gproc dependency. woops.
build: eunit target should fail if a test fails
swarm: add gen_server supervisor

- manages overall swarm relationship to peers
- ensures linkage between swarm and channels via gproc
worker: stop on swarm_id not root_hash
options: use swarm_id instead of root_hash when binary instead of string data