Refactor: Remove Config option for async functions

Refactor: Remove Config option for async functions
Refactor: Update README.md
Refactor: Update async function handler example

Author: Keyur

README.md

@@ -263,10 +263,6 @@ options.maskContent = function(moesifEvent) {
 Type: `Boolean`
 Set to true to print debug logs if you're having integration issues. 
 
-#### __`promisedBased`__
-Type: `Boolean`
-Set to true while using aws lambda async functions. For more details, please refer to - https://docs.aws.amazon.com/lambda/latest/dg/nodejs-handler.html. 
-
 For more documentation regarding what fields and meaning,
 see below or the [Moesif Node API Documentation](https://www.moesif.com/docs/api?javascript).
 
@@ -301,7 +297,8 @@ If you want to capture all outgoing API calls from your Node.js app to third par
 Stripe or to your own dependencies, call `startCaptureOutgoing()` to start capturing.
 
 ```javascript
-var moesifMiddleware = moesifExpress(options);
+const moesif = require('moesif-aws-lambda');
+var moesifMiddleware = moesif(options);
 moesifMiddleware.startCaptureOutgoing();
 ```
 

app.js

@@ -50,9 +50,7 @@ exports.handler = function (event, context, callback) {
 };
 
 // Async Functions 
-// Please set promisedBased configuration flag to true while using async functions. For more details, please refer to - https://docs.aws.amazon.com/lambda/latest/dg/nodejs-handler.html.
-
-// moesifOptions.promisedBased = true; 
+// For more details, please refer to - https://docs.aws.amazon.com/lambda/latest/dg/nodejs-handler.html.
 
 // exports.handler = async (event, context) => {
 //   const response = {

lib/index.js

@@ -156,31 +156,25 @@ module.exports = function (options, handler) {
   var moesifMiddleware = function (event, context, callback) {
     moesifConfigManager.tryGetConfig();
 
-    if (callback && typeof callback === 'function' && !options.promisedBased) {
       logMessage(options.debug, 'moesifMiddleware', 'start');
       var next = function (err, result) {
         logEvent(event, context, err, result, options, moesifController);
         callback(err, result)
       };
 
-      return handler(event, context, next);
-    } else {
-      var returnedPromise = handler(event, context, callback);
+      const returnPromise = handler(event, context, next);
 
-      if (returnedPromise && returnedPromise.then && typeof returnedPromise.then === 'function') {
-      return returnedPromise.then((result) => {
+     if (returnPromise instanceof Promise) {
+      return returnPromise.then((result) => {
         return logEvent(event, context, null, result, options, moesifController).then(() => {
           return result;
         });
       }).catch((err) => {
         logEvent(event, context, err, {}, options, moesifController);
         throw err;
       });
-    } else {
-      logMessage(options.debug, 'moesifMiddleware', 'Can not log promised based handler, please check your configuration.');
-      return returnedPromise;
-    }
     }
+    return returnPromise;
   };
 
   moesifMiddleware.updateUser = function(userModel, cb) {