Run golangci-lint in CI (#927)

* Setup golangci-lint in CI and local-dev

* Fix linting error or locally disable linter

server_test.go

@@ -91,7 +91,7 @@ func TestServerRun(t *testing.T) {
 	// Make sure server exits when receiving TERM signal.
 	go func() {
 		time.Sleep(2 * time.Second)
-		syscall.Kill(syscall.Getpid(), syscall.SIGTERM)
+		_ = syscall.Kill(syscall.Getpid(), syscall.SIGTERM)
 		done <- struct{}{}
 	}()