Log Message:
py-zeep: updated to 4.0.0

4.0.0
Drop support for Python 2.7, 3.3, 3.4 and 3.5
Remove both the aiohttp and the tornado transport class from Zeep. These can be \ 
moved to their own Python package if anyone is interested.
Add zeep.transports.AsyncTransport which is based on httpx. Note that loading \ 
wsdl files is still a sync process but operations can be executed via async.
Start adding more typehints to the package

3.4.0
Allow passing xsd.Nil to sequences
Add support for passing custom digest and signature methods during WSSE signing
Fix path resolving during XSD imports