Update messages.json

Author: jchannon

messages.json

@@ -11,6 +11,7 @@
     "1.7.0": "messages/1.7.0.txt",
     "1.8.0": "messages/1.8.0.txt",
     "1.8.1": "messages/1.8.1.txt",
-    "1.8.2": "messages/1.8.2.txt"
+    "1.8.2": "messages/1.8.2.txt",
+    "1.9.0-beta" : "messages/1.9.0-beta.txt",
 
 }