Disallow PHP 7.2 failures, run dev dep build on PHP 7.1

Author: mbabker

.travis.yml

@@ -20,14 +20,13 @@ matrix:
     - php: 5.6
       env: RUN_PHPCS="yes"
     - php: 7.0
-    - php: 7.0
+    - php: 7.1
+    - php: 7.1
       # This empty flag removes the prefer-stable switch to cause dev dependencies to be installed
       env: COMPOSER_FLAGS=""
-    - php: 7.1
     - php: 7.2
     - php: nightly
   allow_failures:
-    - php: 7.2
     - php: nightly
 
 before_script: