Adding more tests and delete fn
diff --git a/openstack/db/v1/instances/fixtures.go b/openstack/db/v1/instances/fixtures.go
index 716fe09..16b4006 100644
--- a/openstack/db/v1/instances/fixtures.go
+++ b/openstack/db/v1/instances/fixtures.go
@@ -146,3 +146,11 @@
 		fmt.Fprintf(w, singleInstanceJson)
 	})
 }
+
+func HandleDeleteInstanceSuccessfully(t *testing.T, id string) {
+	th.Mux.HandleFunc("/instances/"+id, 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)
+	})
+}