add return value to listen method (#44)

resolves #43

Author: mojavelinux

lib/git.js

@@ -433,6 +433,7 @@ class Git extends EventEmitter {
    * @param  {Buffer|String=}   options.key - the key file for the https server
    * @param  {Buffer|String=}   options.cert - the cert file for the https server
    * @param  {Function} callback - the function to call when server is started or error has occured
+   * @return {Git}  - the Git instance, useful for chaining
    */
   listen(port, options, callback) {
       const self = this;
@@ -447,6 +448,7 @@ class Git extends EventEmitter {
       });
 
       this.server.listen(port, callback);
+      return this;
   }
   /**
    * closes the server instance

test/git.js

@@ -604,7 +604,7 @@ test('git', (t) => {
 
     const repos = new GitServer(repoDir);
     const port = Math.floor(Math.random() * ((1 << 16) - 1e4)) + 1e4;
-    repos.listen(port);
+    t.equal(repos.listen(port), repos);
 
     process.chdir(srcDir);
     async.waterfall([