Fix timeout param being incorrectly handled in read()

If the timeout param for read() was set to 0 to indicate that the
request should not timeout it would actually then be set to None which
would instead use the default timeout value.
Add missing documentation for the timeout args

Seems as though the documentation was not updated when the timeout args
were added.
Merge pull request #31 from jerrykan/fix_timeout

Fix timeout param being incorrectly handled in read()