end: image pushing

[cgonyeo]

It would be convenient (once acpush is finished) to be able to specify an image name, and have the image pushed to that location (optionally signing it with https://github.com/appc/acbuild/issues/15).

Something like the following:

acbuild end --keyring ./keys.pub --secret-keyring ./keys.sec quay.io/dgonyeo/mycoolapp

Would generate an aci and asc file, and then push them to quay. I imagine that in the event of push failure the build would be left in progress, so that a push could be reattempted or the ACI could be written to the local filesystem (also with the end command).

[jonboulle]

Waiting on acpush.