New Replacement for Gorilla/mux and other Gorilla tools

[KenWilliamson]

Gorilla/mux and the other Gorilla tools were great while they last, but Gorilla has been archived.

We intend to create a request multiplexer,GRRT, that is a drop-in replacement for Gorilla/mux, but a more maintainable project.
I will take the lead on GRRT to provide a working prototype to use in the many GO projects that I currently maintain.

Some features of GRRT:

1. Clean code
2. TDD
3. Good Docs