Fix List Records command and add test

[johnbintz]

The List Records command was broken, as it was not sending a DNSimple::Domain instance to Records.all. I fixed this, made the class subclass DNSimple::Command to work like other commands, and added a simple spec to ensure basic data was being printed. The tests will need some additional cleanup, and a Cucumber feature will eventually need to be added, but the command works for me now.

[troy]

I just fixed this as well before finding this pull request. @aeden @dje: could one of you merge @johnbintz's patch or my one-liner below and release a new gem? It's a bug that that most CLI users will encounter (http://support.dnsimple.com/discussions/questions/92-cli-dnsimple-recordlist-raises-nomethoderror-exception).

My one-line fix was to replace:

domain_name = args.shift

with:

domain_name = Domain.find(args.shift)

.. so domain_name is a Domain instead of a String. John's is probably cleaner and definitely has better coverage.

[aeden]

Done. New version is 1.2.5. Thanks for keeping on me about it.