cmd: Support double signal handling

Signed-off-by: Kosy Anyanwu <kosy@kinvolk.io>

cmd/habitat-operator/main.go

@@ -112,12 +112,17 @@ func run() int {
 	// Relay these signals to the `term` channel.
 	signal.Notify(term, syscall.SIGINT, syscall.SIGTERM)
 
-	select {
-	case <-term:
+	go func() {
+		<-term
 		level.Info(logger).Log("msg", "received SIGTERM, exiting gracefully...")
-	case <-ctx.Done():
-		level.Info(logger).Log("msg", "context channel closed, exiting")
-	}
+		cancelFunc()
+
+		<-term
+		os.Exit(1)
+	}()
+
+	<-ctx.Done()
+	level.Info(logger).Log("msg", "context channel closed, exiting")
 
 	return 0
 }