Created multiplexer.go file that creates the skeleton implementation of the NetworkMultiplexer interface.  Creates a NetworkMultiplexer struct and for purposes of passing the make test, a NetworkObject struct as well.  I have written in skeletons of he basic functions for the multiplexer with their name and arguments but not have actually implemented anything into the actual functions.  The NetworkObject struct is temporary until as well as a commented out argument in one of the functions because I have not been able to successfully call upon those objects that are declared outside of the multiplexer.go file.