Expose path to the built-in favicon file

The path is available via `loopback.faviconFile`.

lib/loopback.js

@@ -126,6 +126,25 @@ if (loopback.isServer) {
     });
 }
 
+/*
+ * Expose path to the default favicon file
+ *
+ * ***only in node***
+ */
+
+if (loopback.isServer) {
+  /**
+   * Path to a default favicon shipped with LoopBack.
+   *
+   * **Example**
+   *
+   * ```js
+   * app.use(require('serve-favicon')(loopback.faviconFile));
+   * ```
+   */
+  loopback.faviconFile = path.resolve(__dirname, '../favicon.ico');
+}
+
 /*!
  * Error handler title
  */

test/loopback.test.js

@@ -1,3 +1,5 @@
+var it = require('./util/it');
+
 describe('loopback', function() {
   var nameCounter = 0;
   var uniqueModelName;
@@ -11,6 +13,13 @@ describe('loopback', function() {
       expect(loopback.ValidationError).to.be.a('function')
         .and.have.property('name', 'ValidationError');
     });
+
+    it.onServer('includes `faviconFile`', function() {
+      var file = loopback.faviconFile;
+      expect(file, 'faviconFile').to.not.equal(undefined);
+      expect(require('fs').existsSync(loopback.faviconFile), 'file exists')
+        .to.equal(true);
+    });
   });
 
   describe('loopback.createDataSource(options)', function() {
@@ -68,19 +77,19 @@ describe('loopback', function() {
   describe('loopback.remoteMethod(Model, fn, [options]);', function() {
     it("Setup a remote method.", function() {
       var Product = loopback.createModel('product', {price: Number});
-      
+
       Product.stats = function(fn) {
         // ...
       }
-      
+
       loopback.remoteMethod(
         Product.stats,
         {
           returns: {arg: 'stats', type: 'array'},
           http: {path: '/info', verb: 'get'}
         }
       );
-      
+
       assert.equal(Product.stats.returns.arg, 'stats');
       assert.equal(Product.stats.returns.type, 'array');
       assert.equal(Product.stats.http.path, '/info');