Hi Lynn,

you can create additional environment in Cloud Foundry using spaces for this purpose. Then you need to alter your workflow so after accepting PR the app is pushed to staging space, where automated tests are ran to verify PR doesn't brake current functionality. After this verification you can push the app to prod space.

For more information please look at Continuous Delivery practice [1]

Alex Zalesov @ Altoros

[1]: http://martinfowler.com/bliki/ContinuousDelivery.html