fix (logging) Backendless.Logging may not work in CLOUD mode

Author: vengrov

lib/server-code/runners/cloud.js

@@ -2,7 +2,16 @@
 
 const logger        = require('../../util/logger'),
       DriverService = require('../services/driver'),
-      tasksExecutor = require('./tasks/executor');
+      tasksExecutor = require('./tasks/executor'),
+      Backendless   = require('backendless');
+
+function finalize() {
+  if (Backendless.Logging.messagesCount) {
+    return new Promise((resolve, reject) => {
+      return Backendless.Logging.flush(new Backendless.Async(resolve, reject));
+    });
+  }
+}
 
 exports.start = function(opts) {
   logger.info('Starting Cloud Code Runner');
@@ -24,5 +33,5 @@ exports.start = function(opts) {
       });
   }
 
-  return getTask().then(processTask);
+  return getTask().then(processTask).then(finalize);
 };