Upgraded version of @google-cloud/storage (#213)

Author: hiranya911

package-lock.json

@@ -52,8 +52,8 @@
     "@firebase/app": "^0.1.1",
     "@firebase/database": "^0.1.3",
     "@google-cloud/firestore": "^0.11.2",
-    "@google-cloud/storage": "^1.2.1",
-    "@types/google-cloud__storage": "^1.1.1",
+    "@google-cloud/storage": "^1.6.0",
+    "@types/google-cloud__storage": "^1.1.7",
     "@types/node": "^8.0.53",
     "faye-websocket": "0.9.3",
     "jsonwebtoken": "8.1.0",