Enable our plugin repository: composer does not aggregate 'repositories' from your dependencies.

Add minimum-stability.

composer.json-dist

@@ -6,6 +6,10 @@
         {
             "packagist": false
         },
+        {
+            "type": "composer",
+            "url": "http://plugins.roundcube.net/"
+        },
         {
             "type": "pear",
             "url": "http://pear.php.net/"
@@ -29,5 +33,6 @@
         "Net_SMTP": "dev-master",
         "pear-pear/Net_IDNA2": ">=0.1.1",
         "pear-pear/Auth_SASL": ">=1.0.6"
-    }
+    },
+    "minimum-stability": "dev"
 }