Just give up on testing old PHP versions

Author: SMillerDev

.travis.yml

@@ -1,17 +1,12 @@
 language: php
 php:
-- '5.6'
-- '7.0'
 - '7.1'
 - '7.2'
 - nightly
 env: # important!
 matrix:
   allow_failures:
-  - php: 
-    - 5.6
-    - 7.0
-    - nightly
+  - php: nightly
 
 before_script:
 - travis_retry composer self-update