Merge branch '2.8' into 3.2

* 2.8:
  updated deps
  updated deps
  explicitly declare supported Twig versions
  updated VENDORS for 2.8.17
  updated VENDORS for 2.7.24
  updated VENDORS for 2.8.16
  updated VENDORS for 2.7.23

Author: fabpot

composer.json

@@ -21,7 +21,8 @@
         "symfony/polyfill-apcu": "^1.0",
         "sensio/distribution-bundle": "^5.0",
         "sensio/framework-extra-bundle": "^3.0.2",
-        "incenteev/composer-parameter-handler": "^2.0"
+        "incenteev/composer-parameter-handler": "^2.0",
+        "twig/twig": "^1.0||^2.0"
     },
     "require-dev": {
         "sensio/generator-bundle": "^3.0",