Added master/worker pm2 detection and mail configuration

imports/startup/server/isMaster.js

@@ -0,0 +1,16 @@
+/* eslint-disable import/no-absolute-path */
+
+import pm2Master from 'pm2-master';
+import { Meteor } from 'meteor/meteor';
+
+Meteor.startup(() => {
+  if (pm2Master.isMaster()) {
+    console.log('This is the master process');
+  } else {
+    console.log('This is a worker process');
+  }
+});
+
+const isMaster = () => pm2Master.isMaster();
+
+export default isMaster;