Allow installing stable dependencies.

Author: makasim

composer.json

@@ -8,7 +8,7 @@
     "require": {
         "php": "^7.1.3",
         "queue-interop/queue-interop": "^0.7",
-        "enqueue/dsn": "0.9.x-dev",
+        "enqueue/dsn": "^0.9",
         "thruway/pawl-transport": "^0.5.0",
         "voryx/thruway": "^0.5.3"
     },