Retrieving A Single Row From A Table Implemented

I have implemented retrieving a single row from a table.

Example 

```
<?php
// require the ToyDB autoloader
require_once '/path/to/autoload.php'; 
use BiswarupAdhikari\ToyDB\DataBase;
//Create a ToyDB Instance 
$db=new DataBase("root",123456);
//Select DataBase if not exist it will create automatically
$db->selectDB("mydb");
//List All Products Whose price greater than 2
$row=$db->select('id,product_name,price')
			->from('my_products')
			->where('`id`==2')
			->first();
echo '<pre>';
print_r($row);
echo'</pre>';
```
## License