[RFC] Parallel service packaging

[alice-byb]

Problem

When deploying a set of services, a significant improvement to deployment speed is to package all the services prior to deployment. With a single serverless stack this happens by running serverless package then serverless deploy.

For us, we have a CI approval stage that allows us to package all of our services then approve & deploy each deployment as per our dependency tree.

When working with serverless compose, it's not possible to package all the services in parallel, but is possible to package each individually like:

serverless some-repo:package

we are working around this functionality at the moment by running each individual command in parallel via CI parallelization.

Proposal

Adding a new command (potentially serverless package) that would allow parallel packaging of all services for a single job