Change endpoint from /api/auth/keygen to /api/apikeys/keygen

[BenFradet]

As a spin off of #60, it'd be nice to change the API key generation service endpoint from:

/api/auth/keygen

to:

/api/apikeys/keygen

In order to be more consistent with the existing schema service endpoint:

/api/schemas

[alexanderdean]

As in, schemas and apikeys are both concrete nouns whereas 'auth' is a more amorphic concept?

[BenFradet]

Yes and the fact that the auth endpoint doesn't really perform authentication but only key administration (generation, deletion, and soon retrieval with #60).

[alexanderdean]

Good call