TUN-4067: Reformat code for consistent import order, grouping, and fix formatting. Added goimports target to the Makefile to make this easier in the future.

connection/observer_test.go

@@ -67,10 +67,9 @@ func TestObserverEventsDontBlock(t *testing.T) {
 	}
 }
 
-
 type eventCollectorSink struct {
 	observedEvents []Event
-	mu sync.Mutex
+	mu             sync.Mutex
 }
 
 func (s *eventCollectorSink) OnTunnelEvent(event Event) {
@@ -83,4 +82,4 @@ func (s *eventCollectorSink) assertSawEvent(t *testing.T, event Event) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	assert.Contains(t, s.observedEvents, event)
-}
+}