buildenv: staging GKE needs smaller nodes

Change-Id: If5b496b55cfff83df157c611ec6f289fe745a8ac
Reviewed-on: https://go-review.googlesource.com/38295
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/buildenv/envs.go b/buildenv/envs.go
index 9154395..a3f5e81 100644
--- a/buildenv/envs.go
+++ b/buildenv/envs.go
@@ -164,7 +164,7 @@
 	KubeMinNodes:    1,
 	KubeMaxNodes:    2,
 	KubeName:        "buildlets",
-	KubeMachineType: "n1-standard-32",
+	KubeMachineType: "n1-standard-8",
 	DashURL:         "https://go-dashboard-dev.appspot.com/",
 	CoordinatorURL:  "https://storage.googleapis.com/dev-go-builder-data/coordinator",
 	CoordinatorName: "farmer",