Use ginkgomon to run external processes in main_test
Use ginkgomon to run external processes in main_test

Should make it easier to switch to in-process dummies for the backends and healthchecks

[#83500090]

cloudfoundry-incubator/switchboard,cloudfoundry-incubator/switchboard,cloudfoundry-incubator/switchboard,cloudfoundry-incubator/switchboard