Drop support for PHP 5.4 and 5.5

mnapoli · mnapoli · commit 5cc59fdc0a95 · 2018-12-19T09:13:52.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -3,12 +3,11 @@ language: php
 sudo: false
 
 php:
-  - 5.4
-  - 5.5
   - 5.6
   - 7.0
   - 7.1
   - 7.2
+  - 7.3
 
 cache:
   directories:
