Fixed travis configuration

Author: francisbesset

.travis.yml

@@ -12,7 +12,7 @@ env:
   - SYMFONY_VERSION=2.3.*
   - SYMFONY_VERSION=2.4.*
   - SYMFONY_VERSION=2.5.*
-  - SYMFONY_VERSION=dev-master symfony/debug:~2.6@dev symfony/http-kernel:~2.6@dev
+  - SYMFONY_VERSION="dev-master symfony/debug:~2.6@dev symfony/http-kernel:~2.6@dev"
 
 before_script:
   - composer self-update
@@ -26,4 +26,4 @@ script:
 
 matrix:
   allow_failures:
-    - env: SYMFONY_VERSION=dev-master
+    - env: SYMFONY_VERSION="dev-master symfony/debug:~2.6@dev symfony/http-kernel:~2.6@dev"