Update johnbillion/query-monitor requirement from ^3.15.0 to ^3.16.0

Updates the requirements on [johnbillion/query-monitor](https://github.com/johnbillion/query-monitor) to permit the latest version.
- [Release notes](https://github.com/johnbillion/query-monitor/releases)
- [Commits](johnbillion/query-monitor@3.15.0...3.16.0)

---
updated-dependencies:
- dependency-name: johnbillion/query-monitor
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

composer.json

@@ -17,7 +17,7 @@
  ]
  },
  "require": {
- "johnbillion/query-monitor": "^3.15.0",
+ "johnbillion/query-monitor": "^3.16.0",
  "altis/dev-tools-command": "^0.7.2",
  "wp-phpunit/wp-phpunit": "6.3.1",
  "yoast/phpunit-polyfills": "^1.1.1",