set minimum version to php 5.4

core/testMinimumPhpVersion.php

@@ -16,7 +16,7 @@
 $piwik_errorMessage = '';
 
 // Minimum requirement: stream_resolve_include_path, working json_encode in 5.3.3, namespaces in 5.3
-$piwik_minimumPHPVersion = '5.3.3';
+$piwik_minimumPHPVersion = '5.4.0';
 $piwik_currentPHPVersion = PHP_VERSION;
 $minimumPhpInvalid = version_compare($piwik_minimumPHPVersion, $piwik_currentPHPVersion) > 0;
 if ($minimumPhpInvalid) {