Update travis config

.travis.yml

@@ -2,10 +2,16 @@ language: php
 
 sudo: false
 
+services:
+  - mysql
+  - postgresql
+
 php:
   - 7.0
   - 7.1
-  - hhvm
+  - 7.2
+  - 7.3
+  - 7.4
 
 install:
   - composer install --dev --no-progress