Packer.py

BUG FIXES:
* fix variable reference logic

OTHER:
* update test coverage

BUG FIXES:
* fix failing builds. Switch travis-ci to use tox, disable python3 builds for now

OTHER:
* update descriptions in setup.py
* add copyright header to py files

* support passing template as file path or directly via template parameter [GH-3]
* add test coverage, fix python 3 compatibility [GH-1]

* fixed releasing an empty module :/

* initial release