Updated travis config to include testify
Implemented ChannelMessenger and added tests.
Implemented listener and added tests.
Refactored to remove all refences of network message sending from client.
Changed listener to use a message handler callback rather than a channel. A channel would essentially require the user to reimplement the listener.
Changed callback to be an interface to allow access to client methods and data when handling a message.
Removed raw channel handling from client, since now handled by messenger and listener.
Changed client tests to match new structure.
Added mock messenger.
Implemented test for Barrier.
Added test for broadcast.
Fixed bug with client writing address as message target instead of tcp address.
Finished test for update active members.
Made all channel messengers share a single resolver map to ensure they all stay in sync.
Commit before factoring out the memberlist portion.
Factored out memberlist for MemberTracker and added empty tests for membertracker.
Implemented creation, joining, and leaving for list backed member tracker.
Fixed errors with starting clients for integration test.
Added WaitActive test.
Got the initial integration test working.