[GitHub] Use the content API, which is one HTTP call.

Fixes #7
[job] Tear almost everything out. We perform only one step now and not async.
[version] Store pod in Specs subdir.
Make specs green.
[version] Dynamically generate resource path.
[pods] Either create and publish a pod version or fail.
[pods] Show overview of a pod.
Small cleanup.
[pods] Use PATCH when adding owners.
[bin] Remove worker, no longer needed.
[pods] Only assign the submitter as the owner of a pod once the first version has been published.
Small cleanup.
[db] Squash migrations.