Docker, makefile, versioning, and go get

[danielkrainas]

I can break these up into multiple PRs if you'd like but thought you might appreciate just the one.

Several improvements:

• adds Docker build support
• Makefile for building distributable artifacts
• project VERSION file and versioning baked into executables
• easy install with go get ...
• adds run and version sub-commands

[danielkrainas]

This also includes changes from #4 so if you go with this PR - I'll close that one