Update returnTo middleware

by default express doesn't do case sensitive routing, so `/login` & '/LogIn' are treated same.

app.js

@@ -87,7 +87,7 @@ app.use(function(req, res, next) {
   // Keep track of previous URL
   if (req.method !== 'GET') return next();
   var path = req.path.split('/')[1];
-  if (/(auth|login|logout|signup)$/.test(path)) return next();
+  if (/(auth|login|logout|signup)$/i.test(path)) return next();
   req.session.returnTo = req.path;
   next();
 });