Update to Xcode 11.2

[madsolar8582]

Description of Changes

Update CI image to Xcode 11 and apply recommended settings.

Motivation and Context

Migrating to latest Xcode to ensure compatibility and apply recommended settings to leverage best practices and leverage new quality checks.

How Has This Been Tested?

Local and CI successful builds.

[erikdoe]

It looks like the build on TravisCI is failing. I only had a cursory look at the output and couldn't immediately see what's wrong, but this needs fixing.

I'm also not sure about mixing a number of different concerns in this single PR, but I will comment on them individually.

[madsolar8582]

Looks like the Travis build failed for this particular run due to an issue in Apple's simulator control. My build of the same commit succeeded: https://travis-ci.com/madsolar8582/ocmock/builds/90191297

[erikdoe]

Good news, I re-ran the build manually and it passed now.

[madsolar8582]

Thanks Erik. I merged your current changes onto this branch.

[erikdoe]

To be honest, I'd feel better to wait until Xcode 11 has left beta and is generally available.

For future PRs: it was slightly confusing to see a PR with the title "Update to Xcode 11" and a date of November 2018. For a moment I thought I had missed something. Would be good open a new PR instead of repurposing an old one.

[erikdoe]

Thank you for submitting these PR's. It seems you're always a step ahead of what's available through normal channels. I will now update to Xcode 11.1, which is, according to the AppStore, the current version.