Add phpunit-bridge to detect deprecations

Author: Carlo Forghieri

.travis.yml

@@ -14,7 +14,12 @@ matrix:
   fast_finish: true
   include:
     - php: 5.3
-      env: COMPOSER_FLAGS="--prefer-lowest"
+      env:
+          - COMPOSER_FLAGS="--prefer-lowest"
+          - NO_PHPUNIT_BRIDGE=1
+    - php: 5.4
+      env:
+          - NO_PHPUNIT_BRIDGE=1
     - php: 5.6
       env: SYMFONY_VERSION=2.3.*
     - php: 5.6
@@ -40,6 +45,7 @@ cache:
 before_script:
   - composer selfupdate
   - if [ "$SYMFONY_VERSION" != "" ]; then composer require "symfony/symfony:${SYMFONY_VERSION}" --no-update; fi;
+  - if [ "$NO_PHPUNIT_BRIDGE" == "" ]; then composer require symfony/phpunit-bridge; fi;
   - composer update --prefer-dist $COMPOSER_FLAGS
 
 script: