a mistake in tests/identity/v3/test_role.py

Change test_service_show to test_role_show.

Change-Id: Ieef7fdeb9401b4dc28720c9ba14bf460ac171288

Author: wanghonghw

openstackclient/tests/identity/v3/test_role.py

@@ -715,7 +715,7 @@ def setUp(self):
         # Get the command object to test
         self.cmd = role.ShowRole(self.app, None)
 
-    def test_service_show(self):
+    def test_role_show(self):
         arglist = [
             identity_fakes.role_name,
         ]