Merge pull request propelorm#467 from jaugustin/1.6

add php 7.1, 7.2, to travis ci, allow failure only for php 7.2

Author: jaugustin

.travis.yml

@@ -6,6 +6,8 @@ php:
     - 5.5
     - 5.6
     - 7.0
+    - 7.1
+    - 7.2
     - hhvm
 
 cache:
@@ -20,7 +22,7 @@ matrix:
     fast_finish: true
 
     allow_failures:
-        - php: 7.0
+        - php: 7.2
         - php: hhvm
 
 before_install: