Add PATCH support. See #2, still awaiting tests.

Unable to add tests at the moment, as httpbin's /patch endpoint is broken and refuses to accept PATCH requests

library/Requests.php

@@ -54,6 +54,14 @@ class Requests {
 	 */
 	const DELETE = 'DELETE';
 
+	/**
+	 * PATCH method
+	 *
+	 * @link http://tools.ietf.org/html/rfc5789
+	 * @var string
+	 */
+	const PATCH = 'PATCH';
+
 	/**
 	 * Current version of Requests
 	 *
@@ -221,6 +229,18 @@ public static function post($url, $headers = array(), $data = array(), $options
 	public static function put($url, $headers = array(), $data = array(), $options = array()) {
 		return self::request($url, $headers, $data, self::PUT, $options);
 	}
+
+	/**
+	 * Send a PATCH request
+	 *
+	 * Note: Unlike {@see post} and {@see put}, `$headers` is required, as the
+	 * specification recommends that should send an ETag
+	 *
+	 * @link http://tools.ietf.org/html/rfc5789
+	 */
+	public static function patch($url, $headers, $data = array(), $options = array()) {
+		return self::request($url, $headers, $data, self::PATCH, $options);
+	}
 	/**#@-*/
 
 	/**

library/Requests/Transport/cURL.php

@@ -89,8 +89,9 @@ public function request($url, $headers = array(), $data = array(), $options = ar
 				curl_setopt($this->fp, CURLOPT_POST, true);
 				curl_setopt($this->fp, CURLOPT_POSTFIELDS, $data);
 				break;
+			case Requests::PATCH:
 			case Requests::PUT:
-				curl_setopt($this->fp, CURLOPT_CUSTOMREQUEST, 'PUT');
+				curl_setopt($this->fp, CURLOPT_CUSTOMREQUEST, $options['type']);
 				curl_setopt($this->fp, CURLOPT_POSTFIELDS, $data);
 				break;
 			case Requests::DELETE:

library/Requests/Transport/fsockopen.php

@@ -63,6 +63,7 @@ public function request($url, $headers = array(), $data = array(), $options = ar
 		switch ($options['type']) {
 			case Requests::POST:
 			case Requests::PUT:
+			case Requests::PATCH:
 				if (isset($url_parts['path'])) {
 					$path = $url_parts['path'];
 					if (isset($url_parts['query'])) {