[config/global] Refactor validate method
[config] Refactor class constant layout
[config] Add I18n error messages
[config/global] Finish refactoring
[config/pe_bootstrap] Refactor validate
[plugin] Update require path for config/*
[pe_bootstrap] Add autosign config option
[provisioner/pe_bootstrap] Use on_machine mixin
[provisioner/pe_bootstrap] Extract provisioner postinstall
Merge branch 'autosign-configuration'