Marketplace: one authenticator for two aiidalab apps

[unkcpz]

I add the openapi yaml files for both QeAPP and SSSPapp, but there is a problem registering them both in one jupyterhub, since the two marketplace applications have different id and secret for authenticator, but in our condition, they share the same authenticator.
I think there are two ways for this issue, 1. we deploy them in different servers. 2. Modify the _get_hearder method of an authenticator, so it can authenticate for both applications.

The second option is more what we expected from start, and I don't think have only one aiidalab app in a server is a good idea. I will try to implement the second option but in another PR.

Originally posted by @unkcpz in #20 (comment)