[Development] Upgrade the XCode running in the CI's macOS 10.11

[Thiago Macieira]

On Monday, 9 July 2018 02:39:05 PDT Alexandru Croitor wrote:
> we are using XCode 8.2, and the last supported version on 10.11 is 8.2.1. I
> don't think that the patch release will make a big difference though.

Then how about my second request?

> > If that's the latest, can we declare that building Qt on 10.11 is no
> > longer supported for Qt 5.12? I'm not asking about deployment, only
> > building. 

Can we remove 10.11 from the Qt 5.12 CI?

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center