Support hubot api

[miurahr]

#393 is incomplete support for hubot master branch. It produce 404 error for /me? /channels? api access.

because API with auth_token is considered as unauthorized access in routes.rb.

Here is additional fix to #393 PR.
This PR is tested against hubot master.

[miurahr]

In previous PR , I just put API related resources out of constraints (authenticated :user).
Additional https://github.com/miurahr/kandan/commit/e42d51a71c0aad0ed45aa2de2112236efac51f75 aim to explicitly authenticate as user or token.

Because it is not working for channels:activities nested resource, put these out of authorized_or_have_token constraints. welcome suggestions!

[coveralls]

Coverage decreased (-0.64%) to 69.21% when pulling e42d51a on miurahr:support_hubot_api into 4a7d912 on kandanapp:master.

[miurahr]

Due to a failure of Travis CI test, I've reverted last modifications. It will be tried again in a separate PR.

[miurahr]

Drop here and I'd like to submit cleaned PR agian.