Create a Dockerfile to build the Linux binary

[machawk1]

Per #2, using wxPython on Linux is involved. I found myself utilizing an Ubuntu 18.10 VM but that was slow, lacks an official wxPython wheel (only Ubuntu up to 18.04), required a lot of manual configuration, and was awkward to do code changes to mitigate issues in the Linux port.

This ticket proposes using Docker to build the binary. Initially, no X server will be needed (though wxWidgets/wxPython will likely complain). With volume mounting, this should help to streamline the iterative build process to hopefully one day resolve #2.

• Setup VNC access to the container for WAIL GUI verification