Remove trailing whitespace.
In Item.upload(), check to see if type of the files argument is a
list or tuple, and convert it to a 1-element list if it is not. This
fixes a bug when trying to upload StringIO instances, which have an
__iter__ attribute. Also, in python3, str instances have __iter__ as well.
Fix documentation for Item.upload(). metadata should be a keyword arg.
Add upload test. Note that py.test does not automatically run this test.
Merge pull request #26 from rajbot/master

Fix upload bugs and add upload test case.