Converted to class

Converted to class and added namespace.
This will helpful if you use composer or import it into any framework

Example use

    include_once('index.php');
    
    use thecodepress\timestamper\TimeStamper;
    
    echo TimeStamper::time(1385378646)->toJson(); // json output
    
    echo TimeStamper::time(1385378646)->toXml(); // xml output
    
    echo TimeStamper::time(1385378646)->toAssoc(); // normal output
Merge pull request #1 from abhimanyusharma003/patch-1

Converted procedural code in to Object Oriented.