Fixes replace value, as 1.6 was never released.

Author: aaronj-ep

composer.json

@@ -38,7 +38,7 @@
   },
   "replace": {
     "symfony/propel1-bridge": "<=2.8.0",
-    "propel/propel-bundle": "^1.6"
+    "propel/propel-bundle": "1.6.x-dev"
   },
   "suggest": {
     "propel/propel-acl-bundle": "For using the Propel ACL implementation"