In cases where surykatka is used, it's very good that it would write the
status to some file, as otherwise the output has to be read, and then the
status has to be directed to the file, which requires adding one more layer
of complexity.

Allow to skip some top domains like .co.uk

This is low level timeout error, which can happend outside of socket.timeout,
see https://docs.python.org/3/library/exceptions.html#TimeoutError

/reviewed-on !8

The goal is to detect speed regression of website access.

The elapsed time value is updated in the DB only if an arbitrary threshold is modified (<200ms = fast, <500ms = moderate, >500ms = slow).

Cetificates are monitored until they expired.

Calling datetime.datetime.now will produce local time, whereas utcnow will
result with UTC time.

/reviewed-on !2

/reviewed-on nexedi/surykatka!1

Check http status