Adds CHANGELOG entry for #167

CHANGELOG.md

@@ -6,6 +6,46 @@ Versions prior to 1.0 were originally released as `phly/conduit`; please visit
 its [CHANGELOG](https://github.com/phly/conduit/blob/master/CHANGELOG.md) for
 details.
 
+## 2.2.1 - 2018-04-04
+
+### Added
+
+- Nothing.
+
+### Changed
+
+- Nothing.
+
+### Deprecated
+
+- Nothing.
+
+### Removed
+
+- Nothing.
+
+### Fixed
+
+- [#167](https://github.com/zendframework/zend-stratigility/pull/167) fixes an
+  issue with the `PathMiddlewareDecorator` whereby it was using the original
+  request when invoking the handler it creates, instead of prepending the
+  configured path prefix to the request URI created. With the fix, if middleware
+  alters the request path passed to the handler, the changes will now propagate
+  to later middleware. As an example:      
+
+  ```php
+  new PathMiddlewareDecorator('/api', middleware(function ($request, $handler) {
+      $uri = $request->getUri();
+      if (! preg_match('#^/v\d+/#', $uri->getPath())) {
+          $request = $request->withUri($uri->withPath('/v1' . $uri->getPath()));
+      }
+      return $handler->handle($request);
+  }));
+  ```
+  For the request path `/api/books`, the above will now correctly result in
+  `/api/v1/books` being propagated to lower layers of the application, instead of
+  `/api/books`. 
+
 ## 2.2.0 - 2018-03-12
 
 ### Added