fix(server/flash): Api to match documentation

This fixes duplication issues and normalize our use with everyone else

server/boot/authentication.js

@@ -171,9 +171,10 @@ module.exports = function enableAuthentication(app) {
           redirectTo = req.session.returnTo;
         }
 
-        req.flash('success', { msg:
+        req.flash(
+          'success',
           'Success! You have signed in to your account. Happy Coding!'
-        });
+        );
 
         return res.redirect(redirectTo);
       })