Initial implementation of check_end_to_end.

Signed-off-by: Daira Hopwood <david-sarah@jacaranda.org>
Time out if we cannot connect to the server within 10 seconds.

Signed-off-by: Daira Hopwood <david-sarah@jacaranda.org>
Work in progress.

Signed-off-by: Daira Hopwood <daira@leastauthority.com>