[V3] Rename get_credential to show_credential

[GET /resources] methods should be "list_<resource name>s"
or "show_<resource name>", so this patch applies the rule
to credentials client.

Partially implements blueprint consistent-service-method-names

Change-Id: I07c4403e42d6f2c7617f455a8a4f292ff10e7059
diff --git a/tempest/api/identity/admin/v3/test_credentials.py b/tempest/api/identity/admin/v3/test_credentials.py
index 048c53a..5e1c3cc 100644
--- a/tempest/api/identity/admin/v3/test_credentials.py
+++ b/tempest/api/identity/admin/v3/test_credentials.py
@@ -76,7 +76,7 @@
         self.assertEqual(update_body['blob']['access'], new_keys[0])
         self.assertEqual(update_body['blob']['secret'], new_keys[1])
 
-        get_body = self.creds_client.get_credential(cred['id'])['credential']
+        get_body = self.creds_client.show_credential(cred['id'])['credential']
         for value1 in self.creds_list[0]:
             self.assertEqual(update_body[value1],
                              get_body[value1])
diff --git a/tempest/hacking/ignored_list_T110.txt b/tempest/hacking/ignored_list_T110.txt
index 211a7d6..7077313 100644
--- a/tempest/hacking/ignored_list_T110.txt
+++ b/tempest/hacking/ignored_list_T110.txt
@@ -1,5 +1,4 @@
 ./tempest/services/database/json/flavors_client.py
-./tempest/services/identity/v3/json/credentials_client.py
 ./tempest/services/identity/v3/json/identity_client.py
 ./tempest/services/identity/v3/json/policy_client.py
 ./tempest/services/identity/v3/json/region_client.py
diff --git a/tempest/services/identity/v3/json/credentials_client.py b/tempest/services/identity/v3/json/credentials_client.py
index 7d4cf9a..753e960 100644
--- a/tempest/services/identity/v3/json/credentials_client.py
+++ b/tempest/services/identity/v3/json/credentials_client.py
@@ -51,7 +51,7 @@
         body['credential']['blob'] = json.loads(body['credential']['blob'])
         return service_client.ResponseBody(resp, body)
 
-    def get_credential(self, credential_id):
+    def show_credential(self, credential_id):
         """To GET Details of a credential."""
         resp, body = self.get('credentials/%s' % credential_id)
         self.expected_success(200, resp.status)