feat: introduce Backups (#794)

Co-authored-by: Andrew Zammit <zammit.andrew@gmail.com>

Author: stephenplusplus

package.json

@@ -47,8 +47,9 @@
     "api-documenter": "api-documenter yaml --input-folder=temp"
   },
   "dependencies": {
+    "@google-cloud/precise-date": "^2.0.1",
     "@google-cloud/projectify": "^2.0.0",
-    "@google-cloud/promisify": "^2.0.0",
+    "@google-cloud/promisify": "^2.0.3",
     "arrify": "^2.0.0",
     "concat-stream": "^2.0.0",
     "dot-prop": "^5.0.0",