spin deploy should rollback any changes on a CTRL+C

[bacongobbler]

If I cancel the spin deploy command before it finishes, the deployment can end up in an incomplete state. The bindle may be uploaded, but no application has been created.

We should figure out a way to capture that signal and roll back any changes (if possible).

[bacongobbler]

One snag here will be the fact that a bindle is immutable once uploaded. There is no way to delete it from the server. And because POST /api/apps requires the bindle ID to be present on the server, we need to upload at least one bindle ID before calling that endpoint.