Improved parsing of `docker ps`

This will fix, e.g. parsing of commands with two spaces in them.
More reliable command matching.

If docker command is e.g. `sh -c 'cd foo && ./bar'`, then
`docker ps` will show the command as `sh -c cd foo && ./bar`.
Handle this case when matching on container commands.
Merge branch 'master' of github.com:bflad/chef-docker
Add Ubuntu support to cgroup recipe
Rename execution_driver and storage_driver to match Docker terminology
Yak shaving: rubocop fixes for %w literals and extraneous .to_s