Drop PHP 5.4 support + README

Author: JanPetterMG

.travis.yml

@@ -5,7 +5,6 @@ php:
   - 7.0
   - 5.6
   - 5.5
-  - 5.4
   - hhvm
 install:
   - composer install

README.md

@@ -12,7 +12,7 @@ Parser and group determiner optimized for ``robots.txt``, ``X-Robots-tag`` and `
 [![SensioLabsInsight](https://insight.sensiolabs.com/projects/1386c14c-546c-4c42-ac55-91ea3a3a1ae1/big.png)](https://insight.sensiolabs.com/projects/1386c14c-546c-4c42-ac55-91ea3a3a1ae1)
 
 #### Requirements:
-- PHP [5.6+](http://php.net/supported-versions.php)
+- PHP [5.5+](http://php.net/supported-versions.php)
 
 ## Installation
 The library is available for install via [Composer](https://getcomposer.org). Just add this to your `composer.json` file:

composer.json

@@ -29,7 +29,7 @@
     }
   ],
   "require": {
-    "php": ">=5.4.0"
+    "php": ">=5.5.0"
   },
   "require-dev": {
     "phpunit/phpunit": "~4 || ~5",