tests: add more int/number ranges checks

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170607163635.17635-5-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[test_visitor_in_uint() tightened slightly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
