travis - test also w/ PHP 7.2 & nightly

Author: jakubkulhan

.travis.yml

@@ -3,12 +3,18 @@ language: php
 php:
   - 7.0
   - 7.1
+  - 7.2
+  - nightly
 
 env:
   matrix:
     - COMPOSER_FLAGS="--prefer-lowest"
     - COMPOSER_FLAGS=""
 
+matrix:
+  allow_failures:
+    - php: nightly
+
 before_script:
   - travis_retry composer self-update
   - travis_retry composer update ${COMPOSER_FLAGS} --no-interaction --prefer-source