Corrects the following error:
Corrects the following error:

.7/site-packages/mpl_toolkits/basemap/__init__.py", line 4358, in wmsimage
    return self.imshow(imread(io.BytesIO(urllib2.urlopen(img.url).read()),
AttributeError: 'ResponseWrapper' object has no attribute 'url'

It might have something to do with an owslib update

guziy/basemap,matplotlib/basemap,matplotlib/basemap,guziy/basemap