Add php 5.3 to CI and listed as supported

Author: glensc

Diff for: .github/workflows/test.yml

@@ -82,6 +82,7 @@ jobs:
     strategy:
       matrix:
         php:
+          - '5.3'
           - '5.4'
           - '5.5'
           - '5.6'

Diff for: README.md

@@ -10,7 +10,7 @@ Additionally `blame` can be used to show commits that introduced the breakage.
 
 Running parallel jobs in PHP is inspired by Nette framework tests.
 
-The application is officially supported for use with PHP 5.4 to 8.0.
+The application is officially supported for use with PHP 5.3 to 8.0.
 
 ## Table of contents