Moves dialog-polyfill from devDependencies to dependencies (#252)

Author: bojeil-google

package-lock.json

@@ -31,7 +31,6 @@
   "license": "Apache-2.0",
   "devDependencies": {
     "closure-builder": "^2.0.17",
-    "dialog-polyfill": "^0.4.7",
     "firebase-tools": "^3.0.8",
     "fs-extra": "^3.0.1",
     "google-closure-compiler": "^20160713.2.0",
@@ -51,6 +50,7 @@
     "streamqueue": "^1.1.1"
   },
   "dependencies": {
+    "dialog-polyfill": "^0.4.7",
     "firebase": "^4.3.1"
   }
 }