You seem to use Github Pages (it supports HTTPS nowadays) and Cloudflare, so you should force HTTPS with Cloudflare or Github Pages.
Cloudflare Crypto section:

I've taken the steps to enable the SSL support in GitHub Pages. Unfortunately that means the site will be unavailable over https for up to an hour while GitHub does the ACME dance with letsencrypt.org
..or just the time it took to post that reply!
> GET / HTTP/1.1
> Host: loopback.io
> User-Agent: curl/7.54.0
> Accept: */*
>
< HTTP/1.1 301 Moved Permanently
< Server: GitHub.com
< Content-Type: text/html
< Location: https://loopback.io/
Done. 馃敀
Most helpful comment
..or just the time it took to post that reply!
Done. 馃敀