------------------
- Add support HTTP authentication (mcordes). This adds a new attribute to the
Transport client() which passes the http_auth value to requests. (31)
- Fix issue where setting cache=None to Transport class didn't disable
caching.
- Refactor handling of wsdl:imports, don't merge definitions but instead
lookup values in child definitions. (40)
- Remove unused namespace declarations from the generated SOAP messages.
- Update requirement of six>=1.0.0 to six>=1.9.0 (39)
- Fix handling of xsd:choice, xsd:group and xsd:attribute (30)
- Improve error messages
- Fix generating soap messages when sub types are used via xsd extensions (36)
- Improve handling of custom soap headers (33)