mock-core-configs-32.6-1

Full release notes:
https://github.com/rpm-software-management/mock/wiki/Release-Notes-2.2

• the site-defaults.cfg file moved from mock to mock-core-configs
• new option config_opts['isolation'], obsoletes 'use_nspawn'
• declare minimal version of mock, and set this to v2.2 as we use the new
  'isolation' config option now, and we provide site-defaults.cfg file
• specify amazonlinux bootstrap image, to fix --use-bootstrap-image
• allow to replace mock-core-configs by packages that 'Provides: mock-configs'
• rpmlint: remove macro in comment