update Travis PHP Matrix

Author: mikaelcom

.travis.yml

@@ -5,11 +5,16 @@ sudo: false
 matrix:
   include:
     - php: 5.4
+      dist: trusty
     - php: 5.5
+      dist: trusty
     - php: 5.6
+      dist: trusty
     - php: 7.0
     - php: 7.1
     - php: 7.2
+    - php: 7.3
+    - php: 7.4
 
 install:
     - composer install