Added __invoke() to SignalTrap and fixed phpunit xml

examples/signaltraps.php

@@ -9,8 +9,15 @@ use NoccyLabs\Ipc\Signal\SignalTrap;
 $trap = new SignalTrap(SIGINT);
 echo "Press ctrl-c...\n";
 
-while (!$trap->isTrapped()) {
+while (!$trap->isTrapped(true)) {
     usleep(10000);
 }
 
-echo "Thanks!\n";
+echo "Thanks!\n";
+echo "And once more...\n";
+
+while (!$trap(true)) {
+    usleep(10000);
+}
+
+echo "Thanks!\n";