Log Message:
py-zeep: updated to 3.3.1

3.3.1:
 - Fix issue with empty xsd:import statements on Python 2.7

3.3.0:
 - Extend the force_https flag to also force loading xsd files from https when
   a http url is encountered from a https domain
 - Fix handling recursive xsd imports when the url's are enforced from http to
   https.
 - Fix reference attribute when using the Binary Security Token
 - Add support for the WSAM namespace

3.2.0:
 - Fix abstract message check for NoneType before attempting to access parts
 - Improve support for 'Chameleon' XSD schemas
 - Fix resolving qualified references
 - Fix issue with duplicate soap:body tags when multiple parts used
 - Fix Choice with unbound Any element
 - Add xsd_ignore_sequence_order flag
 - Add support for timestamp token in WSS headers
 - Accept strings for xsd.DateTime

3.1.0:
 - Fix SSL issue on with TornadoAsyncTransport
 - Fix passing strict keyword in XML loader
 - Update documentation

3.0.0:
This is a major release, and contains a number of backwards incompatible
changes to the API.
 - Refactor the settings logic in Zeep. All settings are now configured using
   the zeep.settings.Settings() class.
 - Allow control of defusedxml settings via zeep.Settings
 - Add ability to set specific http headers for each call
 - Skip the xsd:annotation element in the all:element
 - Add Settings.force_https as option so that it can be disabled
 - Strip spaces from QName's when parsing xsd's
 - Fix DateTime parsing when only a date is returned
 - Fix handling of nested optional any elements
 - Check if part exists before trying to delete it