fixing rails4 compatibility

hey, as i needed to extend the client a bit and we're working on rails4 i first had to get the specs passing. these are the changes i made. i also had to bump the database_cleaner version to 1.0.1 (which is working with rails4 but all versions > 1.1 currently don't work with sqlite).

i'm going to open another PR for the extension i made to the client. then you can decide if this would be useful for other people as well.

cheers,
johannes.