fix example and add yarn lock

example/index.js

@@ -2,21 +2,25 @@ var fps = require('node-fps-hk')
 var qrimage = require('qr-image');
 var http = require('http');
 
-http.createServer(function (req, res) {
-    if (req.url == '/') {
-        fps.setMerchantID("0000001");
-        fps.setBillNumber("0002");
-        fps.setStoreLabel("0003");
-        fps.setLoyaltyNumber("0004");
-        fps.setCustomerLabel("0005");
-        fps.setTerminalLabel("0006");
-        fps.setPurposeOfTransaction("0007");
-        fps.setMobileNumber("12345678");
-        fps.setTransactionAmount("5000");
-        fps.setReferenceLabel("ABCD");
-        var string = fps.generate();
-        var code = qrimage.image(string, { type: 'png' });
-        res.setHeader('Content-type', 'image/png');  //sent qr image to client side
-        code.pipe(res);
-    }
-}).listen(8080);
+const server = http.createServer(function (req, res) {
+  if (req.url == '/') {
+    fps.setMerchantID("0000001");
+    fps.setBillNumber("0002");
+    fps.setStoreLabel("0003");
+    fps.setLoyaltyNumber("0004");
+    fps.setCustomerLabel("0005");
+    fps.setTerminalLabel("0006");
+    fps.setPurposeOfTransaction("0007");
+    fps.setMobileNumber("12345678");
+    fps.setTransactionAmount("5000");
+    fps.setReferenceLabel("HKFPS_TESTING");
+    var string = fps.generate();
+    var code = qrimage.image(string, { type: 'png' });
+    res.setHeader('Content-type', 'image/png');  //sent qr image to client side
+    code.pipe(res);
+  }
+});
+
+server.listen(8080, () => {
+  console.log('Server is running on http://localhost:8080');
+});

example/yarn.lock

@@ -0,0 +1,16 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+http@0.0.0:
+  version "0.0.0"
+  resolved "https://registry.yarnpkg.com/http/-/http-0.0.0.tgz#86e6326d29c5d039de9fac584a45689f929f4f72"
+  integrity sha512-epOGLlKUFT+yxfK9TqXRe7l6CbOk7mbLvzVqAyI05w0xIn+nXcYo0vR4ZBCVJYOyUglOFwtaIbD3d2TmG5ejJQ==
+
+"node-fps-hk@file:..":
+  version "1.0.2"
+
+qr-image@^3.2.0:
+  version "3.2.0"
+  resolved "https://registry.yarnpkg.com/qr-image/-/qr-image-3.2.0.tgz#9fa8295beae50c4a149cf9f909a1db464a8672e8"
+  integrity sha512-rXKDS5Sx3YipVsqmlMJsJsk6jXylEpiHRC2+nJy66fxA5ExYyGa4PqwteW69SaVmAb2OQ18HbYriT7cGQMbduw==