Add `Google-InspectionTool` user agents to bots?

[BastienL]

Following https://github.com/fnando/browser/issues/553, I think it would make sense to add:

• Mozilla/5.0 (compatible; Google-InspectionTool/1.0;) and
• Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5X Build/MMB29P) AppleWebKit/537.36 (KHTML, like Gecko) [Chrome/W.X.Y.Z]

to the list of bots. Those two user agents are used in Rich Result Test and URL inspection from the Google Search Console (documentation).

Adding the Google-InspectionTool token to bots.yml would be sufficient.

I am happy to open a PR if you think it should be added to the list :)