Use consistent naming for enforce_scope option

Tempest and a few other plugins such as manila-tempest-plugin registers
the option to enable scope enforcement tests in the [enforce_scope]
option. This renames the option so that this plugin follows that
standard.

Change-Id: Ibd6962947c64f04ff1948a19c4afe9f26d0b47bb
diff --git a/barbican_tempest_plugin/config.py b/barbican_tempest_plugin/config.py
index c358aee..ad32de6 100644
--- a/barbican_tempest_plugin/config.py
+++ b/barbican_tempest_plugin/config.py
@@ -101,13 +101,11 @@
                      "certificate validation?")
 ]
 
-barbican_rbac_scope_verification_group = cfg.OptGroup(
-    name="barbican_rbac_scope_verification",
-    title="Barbican RBAC Verification Options")
-
-BarbicanRBACScopeVerificationGroup = [
-    cfg.BoolOpt('enforce_scope',
+EnforceScopeGroup = [
+    cfg.BoolOpt('barbican',
                 default=False,
+                deprecated_group='barbican_rbac_scope_verification',
+                deprecated_name='enforce_scope',
                 help="Does barbican enforce scope and user "
                      "scope-aware policies?"),
 ]