Install any missing gems when booting docker
Install any missing gems when booting docker

This runs `bundle install` if there are any missing gems when booting
the containers. `bundle check` ensures we don't unnecessarily run
`bundle install`, which is rather slow.

This avoids having to build the entire image (painfully slow) or having
to bring up a container just to install the gems. I used to do this
with `docker-compose run --rm web bundle install`.

mkllnk/openfoodnetwork,lin-d-hop/openfoodnetwork,Matt-Yorkley/openfoodnetwork,lin-d-hop/openfoodnetwork,Matt-Yorkley/openfoodnetwork,mkllnk/openfoodnetwork,Matt-Yorkley/openfoodnetwork,openfoodfoundation/openfoodnetwork,Matt-Yorkley/openfoodnetwork,openfoodfoundation/openfoodnetwork,openfoodfoundation/openfoodnetwork,mkllnk/openfoodnetwork,lin-d-hop/openfoodnetwork,mkllnk/openfoodnetwork,openfoodfoundation/openfoodnetwork,lin-d-hop/openfoodnetwork