I've used https://www.netlify.com to host 100s of static sites for my clients.

It integrates nicely with GitHub and is blazing fast (distributed, geo-cached CDNs).

Best of all, the team at Netlify knows what it's doing, and founder Matt is very smart and their support responds instantly to any questions, no matter how deeply techie it is or how complex.

[ Disclaimer: I'm not affliated with Netlify. Just happen to love their service as I was looking for this and did an extensive evaluation of various such service providers]