Update .travis.yml

.travis.yml

@@ -1,23 +1,25 @@
 language: php
 
-dist: trusty
-sudo: false
-
 matrix:
   include:
     - php: 5.3
       dist: precise
     - php: 5.4
+      dist: trusty
     - php: 5.5
+      dist: trusty
     - php: 5.6
+      dist: xenial
     - php: 7.0
+      dist: xenial
     - php: 7.1
+      dist: bionic
     - php: 7.2
+      dist: bionic
     - php: 7.3
-    - php: nightly
-  fast_finish: true
-  allow_failures:
-    - php: nightly
+      dist: bionic
+    - php: 7.4
+      dist: bionic
 
 install:
   - composer install --prefer-dist --no-interaction --no-progress