Add support for reading name from environment.yml

The `error_and_exit` code is something that could use a little cleanup.  It would be nice to be able to provide more sane formatting without having to rely on `\n` being inserted everywhere.  I'm thinking there needs to be a `subject` *and* `message` -- the former being a short, online description, the latter providing more context as to how the error might have been reached and how to avoid it.  Neither should container `\n` lines, those should be handled via [textwrap][1].

[1]: https://docs.python.org/2/library/textwrap.html