Update website, C++11 to C++14 (#768)

index.html

@@ -92,7 +92,7 @@
 		<h1>Pistache</h1>
 		<div class="post">
 			<p><code>Pistache</code> is a C++ REST framework written by <a href="https://github.com/oktal">Mathieu Stefani</a> at <a href="http://datacratic.com">Datacratic</a>.
-It is written in pure C++11 and provides a low-level HTTP abstraction.</p>
+It is written in pure C++14 and provides a low-level HTTP abstraction.</p>
 
 <p><code>Pistache</code> provides both an HTTP client and server that can be used to create and query complex web and REST APIs.</p>