Change demos to HTTPS for getUserMedia in Chrome

[Nateowami]

Currently the demos are broken in Chrome because they don't use HTTPS. I've updated URLs in the README to use HTTPS when possible. However, it's still broken, because the demos are (randomly?) redirecting to HTTP. However, you can get HTTPS if you edit the URL in the address bar and try again (at least in Chromium 53).

I'm not sure what's causing the redirect, but it can probably be solved by enforcing HTTPS:

On GitHub, navigate to the main page of the repository. Under your repository name, click Settings. Under "GitHub Pages", select Enforce HTTPS.

By the way, I tried some of the other linked sites (e.g. caniuse, OpenCV), and they don't support HTTPS. Hence they are unchanged.

[antonlvovych]

+1