factor our cluster into run.js

run.js

@@ -0,0 +1,13 @@
+const cluster = require('express-cluster');
+const app = require('./server.js');
+
+activePort = process.env.PORT || 3000;
+
+cluster((worker) => {
+    app.listen(activePort, () => {
+        console.log('worker ' + worker.id + ' is listening on port ' + activePort);
+    });
+}, {
+    'respawn': true, // workers will restart on failure
+    'verbose': true, // logs what happens to console
+});