This commit provides an initial migration of general testing CI
infrastructure to CircleCI.
It uses CircleCI 2.1 paramereterised jobs to provide two base
configurations: a vm based `test-machine`, and docker based
`test-container`.
Jobs that require root, docker, or other similar features require the
machine based jobs, but others should be ran using the `test-container` package
as they are both cheaper and faster to run.
Danielle Lancashire