release 0.4.0

Author: dfreedm

bower.json

@@ -10,8 +10,8 @@
     "HTMLImports"
   ],
   "dependencies": {
-    "MutationObservers": "Polymer/MutationObservers#master",
-    "tools": "Polymer/tools#master"
+    "MutationObservers": "Polymer/MutationObservers#>=0.4.0 <1.0.0",
+    "tools": "Polymer/tools#>=0.4.0 <1.0.0"
   },
   "license": "BSD",
   "private": true,
@@ -22,4 +22,4 @@
     "test",
     "tests"
   ]
-}
+}