increase required php version

composer.json

@@ -20,11 +20,11 @@
     },
     "config":{
         "platform": {
-            "php": "5.5.0"
+            "php": "5.5.9"
         }
     },
     "require": {
-        "php": ">=5.5.0",
+        "php": ">=5.5.9",
         "twig/twig": "~1.0",
         "leafo/lessphp": "~0.5.0",
         "symfony/console": "~2.6.0",

core/testMinimumPhpVersion.php

@@ -19,7 +19,7 @@ $piwik_errorMessage = '';
 // NOTE: when changing this variable, we also need to update
 // 1) api.piwik.org
 // 2) tests/travis/generator/Generator.php
-$piwik_minimumPHPVersion = '5.5.0';
+$piwik_minimumPHPVersion = '5.5.9';
 $piwik_currentPHPVersion = PHP_VERSION;
 $minimumPhpInvalid = version_compare($piwik_minimumPHPVersion, $piwik_currentPHPVersion) > 0;
 if ($minimumPhpInvalid) {

tests/PHPUnit/Integration/ReleaseCheckListTest.php

@@ -28,7 +28,7 @@ class ReleaseCheckListTest extends \PHPUnit_Framework_TestCase
 {
     private $globalConfig;
 
-    const MINIMUM_PHP_VERSION = '5.5.0';
+    const MINIMUM_PHP_VERSION = '5.5.9';
 
     public function setUp()
     {