Added support for docker options device and cap-add

[hvolkmer]

With this change it is possible to configure a container like this:

docker_container 'somecontainer' do
  device "/dev/fuse"
  cap_add "SYS_ADMIN"
end

which will allow in this example for mounting of images inside the container.

[hvolkmer]

The build failed b/c of Rubocop which is fixed in https://github.com/bflad/chef-docker/pull/269/files

[bflad]

LGTM!