Replace abc.abstractproperty with property and abc.abstractmethod

Replace abc.abstractproperty with property and abc.abstractmethod,
as abc.abstractproperty has been deprecated since python3.3[1]

[1]https://docs.python.org/3.8/whatsnew/3.3.html?highlight=deprecated#abc

Change-Id: Idfaf5bb3a0552f1128416821de58dc8e1bb584f0

keystoneclient/tests/unit/auth/test_identity_common.py

@@ -79,7 +79,8 @@ class CommonIdentityTests(object):
 
         self.stub_auth(json=token)
 
-    @abc.abstractproperty
+    @property
+    @abc.abstractmethod
     def version(self):
         """The API version being tested."""
 

keystoneclient/v3/contrib/federation/base.py

@@ -25,7 +25,8 @@ class EntityManager(base.Manager):
 
     resource_class = None
 
-    @abc.abstractproperty
+    @property
+    @abc.abstractmethod
     def object_type(self):
         raise exceptions.MethodNotImplemented