MacOS deployment target issue

[jacobweber]

Thanks for this template -- it's very helpful.

When I ran the Standalone app on Mac OS 10.14.6., I got the error: You have macOS %@. The application requires macOS %@ or later. Not sure what's up with the version string there. But adding this to the top of CMakeLists.txt fixed it:

set(CMAKE_OSX_DEPLOYMENT_TARGET "10.13" CACHE STRING "Minimum OS X deployment version")