feat: require node 10 in engines field (GoogleCloudPlatform#1723)

Co-authored-by: F. Hinkelmann <franziska.hinkelmann@gmail.com>

Author: sofisl

package.json

@@ -5,7 +5,7 @@
  "license": "Apache-2.0",
  "author": "Google Inc.",
  "engines": {
- "node": ">=8.0.0"
+ "node": ">=10"
  },
  "repository": {
  "type": "git",