The urllib, urllib2 and urlparse modules of Python 2 were reorganized
into a new urllib namespace on Python 3. Replace urllib, urllib2 and
urlparse imports with six.moves.urllib to make the modified code
compatible with Python 2 and Python 3.
The initial patch was generated by the urllib operation of the sixer
tool on: bin/* swift/ test/.
Change-Id: I61a8c7fb7972eabc7da8dad3b3d34bceee5c5d93