Make codes endpoints available to clients with scim.create,scim.write or password.write

[#81784306] https://www.pivotaltracker.com/story/show/81784306

Signed-off-by: Madhura Bhave <mbhave@gopivotal.com>
Properly validate a token in the /check_token endpoint
(would rather have complete validation in a single class, rather than relying on different component to validate different parts)
https://www.pivotaltracker.com/story/show/79624214
[#79624214]