New add_http function and times helper

added addhttp
This function ensures passed $url starts with http or https depending on the scheme.

Usage:

$url = 'novaframework.com';
$url = add_http($url); //http://novaframework.com

Added Times helper
This helper will take an array of times and add them together to get a
total time.

use Helpers\Times;

$times = array('10:23:00', '00:15:46', '1:04:56');
$counter = new Times($times);
echo $counter->getTotalTime();
//outputs: 11:43:42