Lock Travis distro so new future defaults will not break the build

WyriHaximus · WyriHaximus · commit 1411ea2e274e · 2020-04-26T20:22:09.000+02:00
diff --git a/.travis.yml b/.travis.yml
@@ -15,6 +15,9 @@ php:
   - 7.4
   - nightly
 
+# lock distro so new future defaults will not break the build
+dist: trusty
+
 matrix:
   allow_failures:
     - php: 5.4
