Update copyright dates

include/beast/http/impl/write.ipp

@@ -1,5 +1,5 @@
 //
-// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
+// Copyright (c) 2013-2017 Vinnie Falco (vinnie dot falco at gmail dot com)
 //
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
@@ -278,7 +278,7 @@ struct write_preparation
         w.init(ec);
         if(ec)
             return;
-  
+
         write_start_line(sb, msg);
         write_fields(sb, msg.fields);
         beast::write(sb, "\r\n");