Version 1.4: Less Dpkg Removal

See #5

Version 1.3: Fewer apt remnants

Includes #3 (run apt-get autoremove after installing, and clean up more /var/lib directories) and #4.

Shrunk the image from 101mb to 100mb.

Version 1.2: Slim base

This version is an exploration into using the debian Docker image's slim variant for our base. It should shave off lots of extraneous pieces.

v1.1 – round 2!

now that we've configured Circle to listen for tags, let's see if it works!