Packaging as a gem for reuse from elsewhere
logic of rspec_helper.rb is moved into lib/ for better reuse
allow a bag other than ENV
doc improvements
Extracted DSL method that create Jenkins instance
added inspection method
exposing the IP address of the container
opening up this method for other SSH work
number of "../../" changes as we move files around, so better to define a single constant that we can refer to
load all the lib files consistently
added more convenience methods
failure to create a controller doesn't require stop/teardown
allowing custom options
ADD prevents caching, which makes it difficult for other fixtures to enhance this.

See https://github.com/dotcloud/docker/issues/880
splitting start! to allow subtypes a chance to modify.

Also defining an additional options
Adding another driver that launches Jenkins into a separate IP address.
somehow it ends up trying to install fuse, which doesn't work inside container
improved error check
allow custom options
No need to allocate unique ports since it runs in its own container.