Simple javascript task

##Challenge: Create grid with users and actions

1. Create simple markup, but it should be pretty enough.

| #Username | #Actions        |
| John Doe  | [Edit] [Remove] |
...

[Add User]

2. Use alert, prompt, confirm for errors, add/edit, remove confirmation. And wrap this actions(modal windows) in Promises. For example when I call prompt to add new user:

dialogPrompt().then(function(data){ 
  // data is user from prompt
  addUser(data);
})

function addUser(username){
  var template = '<li>' + username + '</li>';
  table.appendChild(template);
}

3. You should check simple errors. For example if You put empty user anme in prompt than You should show alert with error message Please, fill user name.

4. You shouldn't save users anywhere (local storage or something else) it can be dynamically. Major things are code quality and good approach with promises.