- Usage of docker containerizer is currently hardcoded, this PR makes it
optional. Default is to enable it if docker is enabled.
- Make IP address to listen on part of service configuration.
Added attributes to nixos/tests/mesos.nix to verify that mesos-slave
attributes work. If the generated attributes are invalid, the daemon
should fail to start.
Change-Id: I5511245add30aba658b1af22cd7355b0bbf5d15c