CircleCI: added iOS 13 job (#1503)
CircleCI: added iOS 13 job (#1503)

Will be useful to validate the tests after CF-547.
Also considering that we support it, I think it's useful to run tests there too.
RevenueCat/purchases-ios,RevenueCat/purchases-ios,RevenueCat/purchases-ios,RevenueCat/purchases-ios,RevenueCat/purchases-ios