Create allowed_example.yaml for every constraint

[ctab]

In the demo directory in the gatekeeper repo we have examples of good (allowed by constraint) resources as well as bad (not allowed by constraint). We should have these for the constraints in this repo also. Besides serving as additional illustration they help serve as the basis for integration testing.

[stale]

This issue/PR has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

[sozercan]

this is done, closing