Adding in ostree, puppet, and docker fixtures

[daviddavis]

The puppet fixture script was disabled a long time ago. We should look
into maybe re-enabling it.

The docker asset would be hard to generate in a container because it'd
require running docker inside docker.

[mdellweg]

You know there is the dind container? But the question is, what do we want to generate as container fixtures?
If this is what was found at the old address, i think we are safe to merge it as is.

[daviddavis]

@mdellweg thanks I did not know there was a dind container. Here's what the docker fixture is doing right now:

pulp-fixtures/docker/gen-fixtures.sh

Lines 41 to 44 in e31a3b0

	# Create output_dir and generate fixture data.
	mkdir "${output_dir}"
	docker pull "$image_name"
	docker save "$image_name" > "${output_dir}/${image_name}.tar"