Allow enqueue 0.8 version.

Author: makasim

composer.json

@@ -8,13 +8,13 @@
         "php": ">=5.6",
         "symfony/framework-bundle": "^2.8|^3",
         "symfony/console": "^2.8|^3",
-        "enqueue/enqueue-bundle": "^0.7@dev",
+        "enqueue/enqueue-bundle": "^0.7@dev|^0.8@dev",
         "php-quartz/bridge": "^0.1@dev"
     },
     "require-dev": {
         "phpunit/phpunit": "~5.5",
         "symfony/browser-kit": "^2.8|^3",
-        "enqueue/null": "^0.7@dev"
+        "enqueue/null": "^0.7@dev|^0.8@dev"
     },
     "autoload": {
         "psr-4": { "Quartz\\Bundle\\": "" },