This will allow us to remove a lot of current boilerplate in individual tests, and move it into the test harness.
Note that this will require updating users of the integration test framework. By moving to a property bag of inputs, we should avoid needing future breaking changes to this API though.
This change adds a `pulumi stack output` command. When passed no
arguments, it prints all stack output properties, in exactly the
same format as `pulumi stack` does (just without all the other stuff).
More importantly, if you pass a specific output property, a la
`pulumi stack output clusterARN`, just that property will be printed,
in a scriptable-friendly manner. This will help us automate wiring
multiple layers of stacks together during deployments.
This fixespulumi/pulumi#659.