fix(deps): update dependency @google-cloud/storage to v7

Author: renovate-bot

background/package.json

@@ -16,7 +16,7 @@
   "dependencies": {
     "@google-cloud/firestore": "^5.0.0",
     "@google-cloud/pubsub": "3.1.0",
-    "@google-cloud/storage": "^6.0.0",
+    "@google-cloud/storage": "^7.0.0",
     "express": "^4.16.4"
   },
   "devDependencies": {

bookshelf/package.json

@@ -15,7 +15,7 @@
   },
   "dependencies": {
     "@google-cloud/firestore": "^5.0.0",
-    "@google-cloud/storage": "^6.0.0",
+    "@google-cloud/storage": "^7.0.0",
     "body-parser": "^1.18.3",
     "express": "^4.16.4",
     "multer": "^1.4.1",