Fix race condition in e2e test script

The build detection relied on looking up the build ID immediately
after a webhook simulation, and then repeatedly querying that build
for status. If the ID lookup beats the build record creation, the
script will time out looking for a nil build.

Look at the build list for status instead to eliminate the race.

hack/test-end-to-end.sh

@@ -143,8 +143,7 @@ curl -s -A "GitHub-Hookshot/github" -H "Content-Type:application/json" -H "X-Git
 
 # Wait for build to complete
 echo "[INFO] Waiting for build to complete"
-BUILD_ID=`$openshift kube list builds --template="{{with index .Items 0}}{{.ID}}{{end}}"`
-wait_for_command "$openshift kube get builds/$BUILD_ID | grep complete" $((40*TIME_MIN)) "$openshift kube get builds/$BUILD_ID | grep failed"
+wait_for_command "$openshift kube list builds | grep -i complete" $((30*TIME_MIN)) "$openshift kube list builds | grep -i failed"
 
 echo "[INFO] Waiting for database pod to start"
 wait_for_command "$openshift kube list pods | grep database | grep Running" $((30*TIME_SEC))