use github maintained gocheck.
magic checksum changes

I'm just changing the checksum to what it expects during my run.

This type of test requires many intimate details of the client
implementaiton, which I don't have. I assume it's the test that's broken
and not the code because the code doesn't seem to have changed, and it's
working anyway. sorry!
tests don't use retrying client.
Merge remote-tracking branch 'origin'

Conflicts:
	s3/multi_test.go
Merge pull request #27 from mwhooker/master

Fix failing unit tests