Add message factory installation to socket client docs

Márk Sági-Kazár · Márk Sági-Kazár · commit 89125262a0ee · 2016-01-27T14:39:08.000+01:00
diff --git a/clients/socket-client.rst b/clients/socket-client.rst
@@ -21,6 +21,8 @@ To install the Socket client, run:
 
     $ composer require php-http/socket-client
 
+.. include:: includes/install-message-factory.inc
+
 Usage
 -----
 
