Fall-through to next middleware if Authorization isn't of type Bearer.

This should allow standard HTTP auth to function in a subsequent
middleware down the stack.

Closes #6

index.js

@@ -33,7 +33,7 @@ OAuth2Provider.prototype.login = function() {
 
     if(req.query['access_token']) {
       atok = req.query['access_token'];
-    } else if(req.headers['authorization']) {
+    } else if((req.headers['authorization'] || '').indexOf('Bearer ') == 0) {
       atok = req.headers['authorization'].replace('Bearer', '').trim();
     } else {
       return next();