Fix: Support trait declaration in 5.4.0+

ezcs incorrectly identifies Traits as class constants.

For example, given the following code:

```php
trait SomeTrait
{

}
```
The following error will be output:
 ` 15 | ERROR | Constants must be uppercase; expected SOMETRAIT but found SomeTrait`

This fixes it by adding a specific check when using php 5.4.0+, as per http://php.net/manual/en/tokens.php