How to set language and locale with xcodebuild

Issue #540

testLanguage and testRegion

-testLanguage language
      Specifies ISO 639-1 language during testing. This overrides the setting for the test action of a
      scheme in a workspace.

-testRegion region
      Specifies ISO 3166-1 region during testing. This overrides the setting for the test action of a
      scheme in a workspace.

xcodebuild -project 'TestApp.xcodeproj' -scheme 'TestAppUITests' -configuration Debug -sdk iphonesimulator -UseModernBuildSystem=YES -destination 'OS=13.2.2,name=iPhone 11,platform=iOS Simulator' -testLanguage ja -testRegion ja_JP test