minor #486 Test against different Symfony versions (WouterJ)

This PR was squashed before being merged into the 1.6.x-dev branch (closes #486).

Discussion
----------

Test against different Symfony versions

This also tests the claim to support Symfony 3

Commits
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5c893e5 Test against different Symfony versions

.travis.yml

@@ -3,8 +3,8 @@ language: php
 sudo: false
 
 cache:
-    directories:
-        - $HOME/.composer/cache
+  directories:
+    - $HOME/.composer/cache
 
 php:
   - 5.3
@@ -17,17 +17,24 @@ php:
 matrix:
   include:
     - php: 5.3
-      env: deps=low
+      env: deps=low SYMFONY_DEPRECATIONS_HELPER=weak
+    - php: 5.6
+      env: SYMFONY_VERSION="2.3.*"
+    - php: 5.6
+      env: SYMFONY_VERSION="2.8.*@dev"
+    - php: 5.6
+      env: SYMFONY_VERSION="3.0.*@dev"
 
 env:
   global:
     - deps=no
 
 before_install:
   - composer self-update
+  - if [ "$SYMFONY_VERSION" != "" ]; then composer require --no-update symfony/symfony:${SYMFONY_VERSION}; fi;
 
 install:
-  - if [ "$deps" = "no" ]; then composer install; fi;
+  - if [ "$deps" = "no" ]; then composer update; fi;
   - if [ "$deps" = "low" ]; then composer --prefer-lowest --prefer-stable update; fi;
 
 script:

composer.json

@@ -36,6 +36,7 @@
         "doctrine/orm": "~2.3",
         "symfony/yaml": "~2.2|~3.0",
         "symfony/validator": "~2.2|~3.0",
+        "symfony/phpunit-bridge": "~2.7|~3.0",
         "twig/twig": "~1.10",
         "satooshi/php-coveralls": "~0.6.1",
         "phpunit/phpunit": "~4"