Use the optimized new method for fetching symmetric encryption key instead of set of keys
Update tests that verify that new method used
adapt integration test script for python3.6 that used in Centos 7/8. Remove default keyword for namedtuple that introduced in python3.7 and --directory parameter for http.server and specify the working directory for fork.
default
keyword for namedtuple that introduced in python3.7 and--directory
parameter forhttp.server
and specify the working directory for fork.Checklist