added support for zookeeper watchers for znodes and the events of znode and deleted. Advantage: one can remove/update registries on the fly
canceling heartbeat event when a node gets partitioned; this is later restarted when the node is updated
all of this does not prevent non-reachable nodes from crashing. This is an idea around making the node manager aware of the nodes which have crashed and eventually restarting them accordingly (supervising involved\?)
0.15 version must be using 0.15 celluloid, I'd say (and specs are using rspec 2.x syntax)
Merge pull request #71 from TiagoCardoso1983/check_on_znode_changes

Ädding support for Zookeeper watchers which might enable live update of node addresses
fix dependencies at specific versions
registries: mongo(id) adapter
registries: do not delete all nodes on single node exit
registries:mongodb: update following 8c319db
spec: push spec global options into one place and select registry BE with DCELL_TEST_ADAPTER env variable(use redis if not set)
spec: update for mongodb following 94efb89
gem: bump celluloid-zmq to v0.16.0
server: bind to first available address
a allow registry BE generate unique ID if it is capable or at least be a little bit smarter in fallback
update node self address when it is ready
Merge branch '0-15-stable-mongodb' into master-next-0

Conflicts:
	dcell.gemspec
Revert "Fixes #54"

This reverts commit ea25c6f22acf07126919792a7a53d96173b52173.
Revert "Fix Explorer to use correct Reel class."

This reverts commit ed71847543d502a84884d78e4fa9b99ca9472b92.
avoid random rspec order
travis: restrict build to master and add mongodb to matrix