update dependencies

Ran a `go get -u` and bumped K8s deps to 1.15.0.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

vendor/github.com/godbus/dbus/export.go

@@ -170,11 +170,8 @@ func (conn *Conn) handleCall(msg *Message) {
 			reply.Body[i] = ret[i]
 		}
 		reply.Headers[FieldSignature] = MakeVariant(SignatureOf(reply.Body...))
-		conn.outLck.RLock()
-		if !conn.closed {
-			conn.out <- reply
-		}
-		conn.outLck.RUnlock()
+
+		conn.sendMessage(reply)
 	}
 }
 
@@ -207,12 +204,14 @@ func (conn *Conn) Emit(path ObjectPath, name string, values ...interface{}) erro
 	if len(values) > 0 {
 		msg.Headers[FieldSignature] = MakeVariant(SignatureOf(values...))
 	}
-	conn.outLck.RLock()
-	defer conn.outLck.RUnlock()
-	if conn.closed {
+
+	var closed bool
+	conn.sendMessageAndIfClosed(msg, func() {
+		closed = true
+	})
+	if closed {
 		return ErrClosed
 	}
-	conn.out <- msg
 	return nil
 }