Update .travis.yml file with new Symfony versions

.travis.yml

@@ -1,30 +1,36 @@
 language: php
 
 php:
-  - 5.4
   - 5.5
   - 5.6
   - 7.0
+  - 7.1
   - hhvm
 
+cache:
+  directories:
+    - $HOME/.composer/cache/files
+
 matrix:
+  fast_finish: true
   include:
     - php: 5.6
       env: SYMFONY_VERSION=2.7.*
     - php: 5.6
       env: SYMFONY_VERSION=2.8.*
     - php: 5.6
       env: SYMFONY_VERSION=3.0.*
-    - php: 5.6
-      env: SYMFONY_VERSION=3.0.*@dev
     - php: 5.6
       env: SYMFONY_VERSION=3.1.*@dev
+    - php: 5.6
+      env: SYMFONY_VERSION=3.2.*@dev
   allow_failures:
     - php: hhvm
 
 before_install:
-  - if [ "$SYMFONY_VERSION" != "" ]; then composer require "symfony/symfony:${SYMFONY_VERSION}" --no-update; fi;
-  - if [ "$SYMFONY_VERSION" = "3.0.*@dev" ] || [ "$SYMFONY_VERSION" = "3.1.*@dev" ]; then perl -pi -e 's/^}$/,"minimum-stability":"dev"}/' composer.json; fi;
+  - if [ "$TRAVIS_PHP_VERSION" != "hhvm" ]; then echo "memory_limit=3072M" >> ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/travis.ini; fi;
+  - if [ "$SYMFONY_VERSION" != "" ]; then composer require "symfony/symfony:${SYMFONY_VERSION}" --no-update; else composer require "symfony/symfony:dev-master"; fi;
+  - if [ "$SYMFONY_VERSION" = "3.1.*@dev" ] || [ "$SYMFONY_VERSION" = "3.2.*@dev" ]; then perl -pi -e 's/^}$/,"minimum-stability":"dev"}/' composer.json; fi;
 
 install:
   - composer update --dev --prefer-source
@@ -34,4 +40,3 @@ script: phpunit
 notifications:
   email:
     - composieux@ekino.com
-