Merge branch '2.7' into 2.8

* 2.7:
  Use PHPUnit 6.0 on PHP 7.* test lines

Author: nicolas-grekas

composer.json

@@ -27,7 +27,7 @@
         "symfony/expression-language": "~2.6|~3.0.0",
         "symfony/http-foundation": "~2.4|~3.0.0",
         "symfony/ldap": "~2.8|~3.0.0",
-        "symfony/validator": "^2.5.9|~3.0.0",
+        "symfony/validator": "~2.7.25|^2.8.18|~3.2.5",
         "psr/log": "~1.0"
     },
     "suggest": {