Add in an active_record_helper

Please consider this pull request as the start of a discussion about if this file is needed.

Feedback welcome.

Thanks.
Maybe I'm missing something, but `before(:all, :type)` would re-connect once per example group of the given type, and we only need to establish the connection once, total, right?  Also, this file should only be required by specs that depend on it so doing it once like this seems OK to me and in fact preferable to your `before(:all, :type)` suggestion.