versioning: Catch an assertion error

* Catch an uncaught assertion error
* Minor pep8 fixes
* Update copyright date
autopkg: Add option to disable colored output

* Add an option to disable colored output. The default value is auto,
which will determine if output is a tty and act accordingly. This can be
overridden by setting --color=yes to force color output, or --color=no
to disable it completely.
* Update copyright date

closes grnet/devflow#2