Changed wording of WIP header

Author: clintongormley

book-docinfo.xml

@@ -1,4 +1,4 @@
-<?page_header <b>PLEASE NOTE:</b><br/>We are working on updating this book for Elasticsearch 2.0. Some content might be out of date.?>
+<?page_header <b>PLEASE NOTE:</b><br/>We are working on updating this book for the latest version. Some content might be out of date.?>
 
 <legalnotice>
   <simpara>
@@ -16,7 +16,7 @@
 
 <abstract>
     <simpara role="page_header">
-      We are working on updating this book for Elasticsearch 2.0. Some content might be out of date.
+      We are working on updating this book for the latest version. Some content might be out of date.
     </simpara>
     <simpara>
         If you would like to purchase an eBook or printed version of this