Get integration test netmap from watch-ipn command (#1729)

hscontrol/util/util.go

@@ -0,0 +1,13 @@
+package util
+
+import "tailscale.com/util/cmpver"
+
+func TailscaleVersionNewerOrEqual(minimum, toCheck string) bool {
+	if cmpver.Compare(minimum, toCheck) <= 0 ||
+		toCheck == "unstable" ||
+		toCheck == "head" {
+		return true
+	}
+
+	return false
+}