Make hugo stop if you send Ctrl+C
Make hugo stop if you send Ctrl+C

While running hugo under Docker, sending a Ctrl+C doesn't make it stop,
only the shell script stops.

(even thought Hugo says "Press Ctrl+C to stop")

Adding the `-i` to Docker changes this behaviour. Hitting Ctrl+C now
causes Hugo to stop, and the shell script to exit.

gomex/devopsdays-web,gomex/devopsdays-web,gomex/devopsdays-web,gomex/devopsdays-web