Don't pass None via UpdateIdentifier

On intial deployment, don't pass None, because this fails validation
inside nested heat templates which reference this parameter via
parameter_defaults.  Instead remove the assignment of UpdateIdentifer
and rely on the defaults specified in the heat templates.

Change-Id: Ia748c00fad86f933117030ffa3e7d0f3044ff66b
Closes-Bug: #1596640

tripleoclient/tests/v1/overcloud_deploy/test_overcloud_deploy.py

@@ -180,7 +180,6 @@ class TestDeployOvercloud(fakes.TestDeployOvercloud):
             'TrovePassword': 'password',
             'ZaqarPassword': 'password',
             'DeployIdentifier': 123456789,
-            'UpdateIdentifier': None,
             'StackAction': 'UPDATE',
         }
 
@@ -349,7 +348,6 @@ class TestDeployOvercloud(fakes.TestDeployOvercloud):
             'TrovePassword': 'password',
             'ZaqarPassword': 'password',
             'DeployIdentifier': 123456789,
-            'UpdateIdentifier': None,
             'StackAction': 'CREATE',
         }
 

tripleoclient/v1/overcloud_deploy.py

@@ -112,7 +112,6 @@ class DeployOvercloud(command.Command):
 
         timestamp = int(time.time())
         parameters['DeployIdentifier'] = timestamp
-        parameters['UpdateIdentifier'] = None
         parameters['StackAction'] = 'CREATE' if stack_is_new else 'UPDATE'
 
         # Update parameters from answers file: