Remove requirement for any extensions

While adding PECL extensions or support for curl is not technically difficult, it can be restricted by the host. Also requiring an extension for a single monitoring method seems overkill. Streams are a php native way to achieve the same thing. 

This was bothering me for a few days so I made the quick and easy fix...

All that was required was to create a context: 
```
$opts = array(
   'http'=> array(
      'method' => 'POST',
      'header' => 'Content-Type: application/json',
      'content' => $body
   )
);
$context = stream_context_create( $opts );
```

then get the contents: 
```
file_get_contents( $url, 0, $context );
```