Extend fakeServer to stop the Marathon client by default.

Add extra CloseServer method for cases where only the server should be
closed.

subscription_test.go

@@ -385,7 +385,7 @@ func TestConnectToSSEFailure(t *testing.T) {
 	config := configContainer{client: &clientCfg}
 
 	endpoint := newFakeMarathonEndpoint(t, &config)
-	endpoint.Close()
+	endpoint.CloseServer()
 
 	client := endpoint.Client.(*marathonClient)
 
@@ -425,7 +425,7 @@ func TestRegisterSEESubscriptionReconnectsStreamOnError(t *testing.T) {
 	time.Sleep(SSEConnectWaitTime)
 
 	// This should make the SSE subscription fail and reconnect to another cluster member
-	endpoint1.Close()
+	endpoint1.CloseServer()
 
 	// Give it a bit of time so that the subscription can reconnect
 	time.Sleep(SSEConnectWaitTime)

testing_utils_test.go

@@ -319,5 +319,10 @@ func (s *fakeServer) Close() {
 }
 
 func (e *endpoint) Close() {
+	e.Client.Stop()
+	e.CloseServer()
+}
+
+func (e *endpoint) CloseServer() {
 	e.Server.Close()
 }