Dedupe patcher in test code
Allow selection of containers by excluded tags
command: tidy up, and add a --version option
command: make requests a bit quieter by default
command: expose the tags and exclude_tags options
Add ability to prevent automatic stopping

This is useful for times when you might want to bring up some new containers
without killing off the old ones, run some healthchecks against them, and add
them to the load balancers before killing off the old ones.
Don't worry about coverage for open()