Fix: Be strict during tests

Author: localheinz

phpunit.xml

@@ -3,6 +3,9 @@
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/4.8/phpunit.xsd"
     backupGlobals="false"
+    beStrictAboutChangesToGlobalState="true"
+    beStrictAboutOutputDuringTests="true"
+    beStrictAboutTestsThatDoNotTestAnything="true"
     bootstrap="./module/Application/test/bootstrap.php"
     colors="true"
     columns="max"