Feature/filestorage securityservices delete (#133)

* sfs: Add support for security services Delete

* sfs: Add acceptance tests for security service Delete
diff --git a/openstack/sharedfilesystems/v2/securityservices/testing/fixtures.go b/openstack/sharedfilesystems/v2/securityservices/testing/fixtures.go
index 78adc48..e6b101a 100644
--- a/openstack/sharedfilesystems/v2/securityservices/testing/fixtures.go
+++ b/openstack/sharedfilesystems/v2/securityservices/testing/fixtures.go
@@ -50,3 +50,11 @@
         }`)
 	})
 }
+
+func MockDeleteResponse(t *testing.T) {
+	th.Mux.HandleFunc("/security-services/securityServiceID", func(w http.ResponseWriter, r *http.Request) {
+		th.TestMethod(t, r, "DELETE")
+		th.TestHeader(t, r, "X-Auth-Token", fake.TokenID)
+		w.WriteHeader(http.StatusAccepted)
+	})
+}