Break up the testing workflow into multiple independent steps

[johndayrichter]

Change the lerna.yml workflow so that testing steps can be run in parallel. At
present, it usually takes between 10 and 20 minutes to run all the preflight checks.

Right now the process is:

1. Bootstrap the project without hoisting
2. Clean the project
3. Bootstrap the project again with hoisting
4. Run the unit tests
5. Run test-docker

And all of these steps are run for all 3 versions of node.

This runs a number of steps in series that could be attacked in parallel, either by clever use of the matrix feature or (perhaps more clearly) breaking them into independent workflows.

[blingdahl]

Where is lerna.yml? I don't see it in the open-product-recovery repo.