Wrap require in Worker with try-catch

Worker._run in async, so throws in it will result in unhandled Promise rejection instead of unhandled exception, and process wont exit.

lib/worker.js

@@ -142,7 +142,13 @@ class Worker extends ClusterProcess {
 
         const workerBase = this.config.resolve('app');
 
-        require(workerBase);
+        try {
+            require(workerBase);
+        } catch (e) {
+            console.error(`Worker failed on require ${workerBase}`);
+            console.error(e);
+            process.exit(1);
+        }
         this.emit('loaded', workerBase);
 
         if (!this.config.get('control.triggerReadyStateManually', false)) {