try to see if php version makes a difference in failing tests

Author: Jeroeny

.travis.yml

@@ -2,10 +2,12 @@ language: php
 
 matrix:
   include:
-    - php: 7.0
+    - php: 7.2
       env: SYMFONY_VERSION=3.4.*
     - php: 7.2
       env: SYMFONY_VERSION=4.0.*
+    - php: 7.4
+      env: SYMFONY_VERSION=5.0.*
 
 before_install:
   - >