Check browser version and block old browsers

[JannisBush]

We are using some "new" javascript features, therefore we might should check the browser of a participant and stop the experiment on old browsers.

The problem is: what are the minimum requirements we have?
And some mobile browsers might fulfill all requirements, but we might still want to block them for some/all experiments.

Also, do we trust our users and just use an easy detection (e.g. console.log(navigator.userAgent);) or do we want a solution that is more reliable?

[x-ji]

I think we also mentioned this before, though in general people who take up MTurk etc. experiments already have a really new version of browser installed. There should already be some browser version detection libraries/packages that could help do the job, and we could try to use them.