Zeep WSDL Parsing Error

zeep_parsing_failure.log

```
17:09 $ python -mzeep 'https://listings.colliershub.com/Services/API/Currencies.svc?wsdl'
Traceback (most recent call last):
  File "/usr/local/Cellar/python/2.7.12_2/Frameworks/Python.framework/Versions/2.7/lib/python2.7/runpy.py", line 174, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/usr/local/Cellar/python/2.7.12_2/Frameworks/Python.framework/Versions/2.7/lib/python2.7/runpy.py", line 72, in _run_code
    exec code in run_globals
  File "/Users/vertrees/.virtualenvs/colliers_testing/lib/python2.7/site-packages/zeep/__main__.py", line 86, in <module>
    main(args)
  File "/Users/vertrees/.virtualenvs/colliers_testing/lib/python2.7/site-packages/zeep/__main__.py", line 75, in main
    client = Client(args.wsdl_file, transport=transport)
  File "/Users/vertrees/.virtualenvs/colliers_testing/lib/python2.7/site-packages/zeep/client.py", line 120, in __init__
    self.wsdl = Document(wsdl, self.transport)
  File "/Users/vertrees/.virtualenvs/colliers_testing/lib/python2.7/site-packages/zeep/wsdl/wsdl.py", line 66, in __init__
    root_definitions.resolve_imports()
  File "/Users/vertrees/.virtualenvs/colliers_testing/lib/python2.7/site-packages/zeep/wsdl/wsdl.py", line 201, in resolve_imports
    binding.resolve(self)
  File "/Users/vertrees/.virtualenvs/colliers_testing/lib/python2.7/site-packages/zeep/wsdl/definitions.py", line 102, in resolve
    self.port_type = definitions.get('port_types', self.port_name.text)
  File "/Users/vertrees/.virtualenvs/colliers_testing/lib/python2.7/site-packages/zeep/wsdl/wsdl.py", line 181, in get
    raise IndexError("No definition %r in %r found" % (key, name))
IndexError: No definition u'{http://tempuri.org/}Currencies' in 'port_types' found
```