gulp server not running on any port - gulp

Question

Hey guys i am new to angularJs so i am learning. i have used xampp before on port 8080 and now when i set up a gulp server it says that it started successfully but nothing appeared on browser. tried to change port but didnt work. what did i do wrong? here is my gulpfile.js
var gulp = require('gulp'),
connect = require('gulp-connect'),
historyApiFallback = require('connect-history-api-fallback');
//Development Web Server
gulp.task('server', function(){
connect.server({
root: './app',
hostname: 'localhost',
port: 2020,
liverload: true,
middleware: function(connect, opt){
return [ historyApiFallback ];
}
});
});
var stylus = require('gulp-stylus'),
nib = require('nib');
//Preprocess Stylus files to CSS and reload changes
gulp.task('css', function(){
gulp.src('./app/stylesheets/main.styl')
.pipe(stylus({use: nib()}))
.pipe(gulp.dest('./app/stylesheets'))
.pipe(connect.reload());
});
//Reload the browser on HTML changes
gulp.task('html', function(){
gulp.src('./app/**/*.html')
.pipe(connect.reload());
});
//watch code changes and to run related tasks
gulp.task('watch' , function(){
gulp.watch(['./app/**/*.html'],['html']);
gulp.watch(['./app/stylesheets/**/*.styl'],['css']);
});
gulp.task('default', ['server', 'watch']);