Make phpunit fail if a --filter does not execute any tests

Author: staabm

phpunit.xml

@@ -4,8 +4,10 @@
 	bootstrap="tests/bootstrap.php"
 	cacheResult="false"
 	colors="true"
+	executionOrder="random"
 	failOnRisky="true"
 	failOnWarning="true"
+	failOnEmptyTestSuite="true"
 	beStrictAboutChangesToGlobalState="true"
 	beStrictAboutCoversAnnotation="true"
 	beStrictAboutOutputDuringTests="true"