Minor improvement. Forces garbage collection before check local memory usage.

Author: fcabralpacheco

test/Response/SapiStreamEmitterTest.php

@@ -205,6 +205,8 @@ public function testEmitMemoryUsage($seekable, $maxBufferLength, $sizeBlocks, $m
 
         ob_end_flush();
 
+        gc_collect_cycles();
+
         $localMemoryUsage = memory_get_usage();
 
         $this->assertLessThanOrEqual($maxBufferLength, $peakBufferLength);