client/input/input.go: GetConfirmation() should communicate
with the user via the io.Writer instance passed in as
argument.
client/keys/add.go: replace cmd.PrintErrln() calls with
fmt.Fprintln(cmd.ErrOrStderr(), ...) because of cobra's
PrintErr* functions broken behaviour. For more information
please see https://github.com/spf13/cobra/pull/894Closes: #6601
Thanks: @noandrea for pointing this out.