Added full instructions for running end-to-end test (#55)

* Added full instructions for running end-to-end test

* Delete integration test namespace after test

* Don't start the old Prometheus integration in the test

Author: jkohen

RELEASE-PROCESS.md

@@ -1,3 +1,13 @@
 # Release Process
 
-Make sure the [end-to-end test](https://github.com/Stackdriver/stackdriver-prometheus-e2e) passes, then run `./release.sh {VERSION}`.
+Make sure the [end-to-end test](https://github.com/Stackdriver/stackdriver-prometheus-e2e) passes:
+```sh
+make DOCKER_IMAGE_TAG=$USER push
+( cd kube ; GCP_REGION=us-central1-a GCP_PROJECT=prometheus-to-sd KUBE_CLUSTER=integration-cluster KUBE_NAMESPACE=$USER SIDECAR_IMAGE_TAG=$USER ./deploy.sh )
+( cd ../stackdriver-prometheus-e2e ; make CLUSTER_NAME=integration-cluster START_PROMETHEUS=false )
+kubectl delete namespace $USER
+```
+
+`START_PROMETHEUS=false` prevents the old Prometheus integration from starting as part of the test.
+
+If OK, then release by running `./release.sh {VERSION}`