Fix: Fix php version constraint to support 5.x

Author: Adeyemi Olaoye

composer.json

@@ -6,7 +6,7 @@
     "license": "MIT",
     "minimum-stability": "stable",
     "require": {
-        "php": "~5.5.0|~7.0",
+        "php": "~5.5|~7.0",
         "yiisoft/yii2": ">=2.0.8",
         "yiisoft/yii2-bootstrap": "*",
         "yiisoft/yii2-swiftmailer": "*",