Removing php 5.4 support

.travis.yml

 language: php
 
 php:
-    - 5.4
     - 5.5
     - 5.6
     - 7.0

composer.json

@@ -18,7 +18,7 @@
         }
     ],
     "require": {
-        "php": ">=5.4.0",
+        "php": ">=5.5.0",
         "ext-pdo": "*",
         "ext-curl": "*"
     },