Fix transient tests

Author: jderusse

Tests/Transport/AmqpExt/AmqpExtIntegrationTest.php

@@ -161,6 +161,9 @@ public function testItReceivesSignals()
         $signalTime = microtime(true);
         $timedOutTime = time() + 10;
 
+        // wait for worker started and registered the signal handler
+        usleep(100 * 1000); // 100ms
+
         // immediately after the process has started "booted", kill it
         $process->signal(15);