File header rule

We could have an opt-in rule that warned when the file have the default comment header included in Xcode template. For example:

```
//
//  LegacyConstructorRule.swift
//  SwiftLint
//
//  Created by Marcelo Fabri on 29/11/15.
//  Copyright © 2015 Realm. All rights reserved.
//
```

This wouldn't be enabled for SwiftLint 😅 
