Can we add the pcntl extension to the container to enforce time limits

[andybroomfield]

Can we add

docker-php-ext-configure pcntl --enable-pcntl && \
docker-php-ext-install pcntl && \

This is so we can use enforceTimeOuts in PHP unit tests.

[andybroomfield]

We might be able to just add pcntl to the list of extensions. Have opened up #46, #47, and #48 to try.
Then use the following to check

docker exec -u docker -t drupal bash -c 'find /usr/local/lib/php/extensions -name "*pcntl*"'