added simplistic dictionary_auth example (#105)

demo/dictionary_auth/users.py

@@ -0,0 +1,10 @@
+from collections import namedtuple
+
+User = namedtuple('User', ['username', 'password', 'permissions'])
+
+user_map = {
+    user.username: user for user in [
+        User('devin', 'password', ('public',)),
+        User('jack', 'password', ('public', 'protected',)),
+    ]
+}