Add signal in the kill CLI commando to send a specific signal to the service

Signed-off-by: Raúl Cumplido <raulcumplido@gmail.com>
Merge pull request #611 from raulcd/604_support_reloading_containers

Add signal in the kill CLI commando to send a specific signal to the service
Bash completion for fig command

Signed-off-by: Harald Albers <github@albersweb.de>