Add payload base classes to prepare for simplifying the client

This change adds payload request and response base classes to
prepare for future simplification updates to the current client
architecture. No new tests are required for this change.

kmip/core/messages/payloads/delete_attribute.py

@@ -20,9 +20,10 @@ from kmip.core import exceptions
 from kmip.core import objects
 from kmip.core import primitives
 from kmip.core import utils
+from kmip.core.messages.payloads import base
 
 
-class DeleteAttributeRequestPayload(primitives.Struct):
+class DeleteAttributeRequestPayload(base.RequestPayload):
     """
     A request payload for the DeleteAttribute operation.
 
@@ -65,9 +66,7 @@ class DeleteAttributeRequestPayload(primitives.Struct):
                 KMIP 2.0+. Optional, defaults to None. Must be specified if the
                 current attribute is not specified.
         """
-        super(DeleteAttributeRequestPayload, self).__init__(
-            enums.Tags.REQUEST_PAYLOAD
-        )
+        super(DeleteAttributeRequestPayload, self).__init__()
 
         self._unique_identifier = None
         self._attribute_name = None
@@ -374,7 +373,7 @@ class DeleteAttributeRequestPayload(primitives.Struct):
             return NotImplemented
 
 
-class DeleteAttributeResponsePayload(primitives.Struct):
+class DeleteAttributeResponsePayload(base.ResponsePayload):
     """
     A response payload for the DeleteAttribute operation.
 
@@ -397,9 +396,7 @@ class DeleteAttributeResponsePayload(primitives.Struct):
                 that was deleted. Used in KMIP 1.0 - 1.4. Defaults to None.
                 Required for read/write.
         """
-        super(DeleteAttributeResponsePayload, self).__init__(
-            enums.Tags.RESPONSE_PAYLOAD
-        )
+        super(DeleteAttributeResponsePayload, self).__init__()
 
         self._unique_identifier = None
         self._attribute = None