Fixed command line arg issue with test

After the migration to Boot we changed the command line arg
format to --zk=host:port. These changes were not reflected
in the tests which caused them to fall back to the default
ZK host:port. I noticed this as a problem after taking down
the ZK server and seeing the tests fail.
Initial module redeployment on container departure

https://github.com/markfisher/xdzk/issues/19
Leader Admin handles container departure

The Curator cache for containers (/xd/containers) is now
initialized and torn down as part of the leadership election
lifecycle. This mirrors the pattern used for the stream cache
(/xd/streams).
Support for module labels

Added support for module labels. Module labels are used in
the stream and deployment paths to ensure unique naming.
Initial container group support

Containers can indicate group membership via command line
argument. Deployments can be targeted to groups. Right now
all group members are sent module deployments; next step
is to allow a configurable number of group members to
take a deployment.
Handle number of containers within a group

The "all" group concept has been removed. Instead a count of
0 should be specified to indicate that all members of a group
should receive a module deployment. If there is no group
specified, then all containers will receive the deployment.