Drop php 5.3 support

.travis.yml

@@ -10,10 +10,6 @@ sudo: false
 matrix:
   fast_finish: true
   include:
-    - php: 5.3
-      env: polyfill='true'
-    - php: 5.3
-      env: polyfill='false'
     - php: 5.4
       env: polyfill='true'
     - php: 5.4

README.md

@@ -1,7 +1,7 @@
 ![Stringy](http://danielstjules.com/github/stringy-logo.png)
 
 A PHP string manipulation library with multibyte support. Compatible with PHP
-5.3+, PHP 7, and HHVM. Refer to the [1.x branch](https://github.com/danielstjules/Stringy/tree/1.x)
+5.4+, PHP 7, and HHVM. Refer to the [1.x branch](https://github.com/danielstjules/Stringy/tree/1.x)
 for older documentation.
 
 ``` php

composer.json

@@ -15,7 +15,7 @@
         }
     ],
     "require": {
-        "php": ">=5.3.0",
+        "php": ">=5.4.0",
         "symfony/polyfill-mbstring": "~1.1"
     },
     "require-dev": {