Fix for #1 Need to ensure password not in browser cache

Author: charlesweir

_includes/head-custom.html

@@ -1,7 +1,9 @@
 <!-- Configuration to go in head section -->
 
 <title>Three Random Words Password Generator</title>
-        
+<meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate">
+<meta http-equiv="Pragma" content="no-cache">
+<meta http-equiv="Expires" content="0">        
 <meta charset="UTF-8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <link rel="shortcut icon" type="image/x-icon" href="images/favicon.ico"/>