Drop browser support, deprecate PhantomJS

So PhantomJS is gone now, but we still do not have the banner merged. As there were raised concerns about it.

  • It would be better of as a notification, in the notification drawer.
    This Implementation has the drawback, that we would eighter had to notify server about it, or change the implementation of the notification drawer.
  • We could implement an complete session manager something like Github have - follow ups in other thread please

I alone am okey with keeping the IE >= 10 support for now, but as I already started, I would like to hear your opinions.

Here is the banner PR:
https://github.com/theforeman/foreman/pull/6776

If we would choose a different aproach, I wouldn’t probably find time in a near future to implement it.

Please share how much you guys think the IE support is costing us, and if we should push this solution further, or implement something as the session manager.

The original plan was to inform users of 1.23 right? I would prefer not to block the warning on session management and go ahead with banner as is. The question here is, are we really dropping IE? 12 votes is probably not enough. How about you bring this topic up on community demo? Also a blog post or other media could be used, cc @rabajaj

That is the main issue I believe. We can’t just drop it, and actually I’m inclined to keep the support if there is not such a big trouble with it, only problem is how to test it.
And as I mentioned in the PR, if we are not convinced the support should be dropped, I do not like the idea of the banner disturbing all the users.