Docker Support

I've created a pseudo-integration-test-bash-hack for TDD.

Before starting on the work, here's the output:

(pulp) [vagrant@pulp2 pulp]$ ./tag-orphan-test.sh 
+----------------------------------------------------------------------+
                   Synchronizing Repository [busybox]
+----------------------------------------------------------------------+

This command may be exited via ctrl+c without affecting the request.

Downloading manifests
[-]
^C+----------------------------------------------------------------------+
                    Publishing Repository [busybox]
+----------------------------------------------------------------------+

This command may be exited via ctrl+c without affecting the request.

[/]
[|]
Waiting to begin...

Task Succeeded

Present. should be present with expected behavior
{
    "    Present (1 tag)": [
        "sha256:186694df7e479d2b8bf075d9e1b1d7a884c6de60470006d572350573bfa6dcd2",
        2
    ]
}
This command may be exited via ctrl+c without affecting the request.

[\]
Running...

Units Removed:
  1
  1

Present. tags removed. sanity check, should still be present until republish
{
    "    Present (1 tag)": [
        "sha256:186694df7e479d2b8bf075d9e1b1d7a884c6de60470006d572350573bfa6dcd2",
        2
    ]
}
+----------------------------------------------------------------------+
                    Publishing Repository [busybox]
+----------------------------------------------------------------------+

This command may be exited via ctrl+c without affecting the request.

Task Succeeded

Present. publish. should (not?) be gone (after fix)... maybe
{
    "    Present (1 tag)": [
        "sha256:186694df7e479d2b8bf075d9e1b1d7a884c6de60470006d572350573bfa6dcd2",
        2
    ]
}
+----------------------------------------------------------------------+
                    Publishing Repository [busybox]
+----------------------------------------------------------------------+

The following publish configuration options will be used:

Force Full:  True

This command may be exited via ctrl+c without affecting the request.

Task Succeeded

Gone(After)Present(before). force full publish. should be gone (after fix)
{
    "    Present (1 tag)": [
        "sha256:186694df7e479d2b8bf075d9e1b1d7a884c6de60470006d572350573bfa6dcd2",
        2
    ]
}
This command may be exited via ctrl+c without affecting the request.

[\]
Running...

Task Succeeded

Gone(after)Present(before) orphans removed. sanity check, should still be present until republish
{
    "    Present (1 tag)": [
        "sha256:186694df7e479d2b8bf075d9e1b1d7a884c6de60470006d572350573bfa6dcd2",
        2
    ]
}
+----------------------------------------------------------------------+
                    Publishing Repository [busybox]
+----------------------------------------------------------------------+

The following publish configuration options will be used:

Force Full:  True

This command may be exited via ctrl+c without affecting the request.

Task Succeeded

Gone(after, before) orphans removed, should still be present until publish
{
    "    Gone: (1 tag)": null
}

https://github.com/pulp/pulp_docker/pull/232

Hack tests pass. Filed a pulp-smash issue.

Applied in changeset c82bfc562dcab2fbbd23f1bcc29f3c4e595f1fea.