Create user connection back-end view/endpoint.

[Lianis-Operations]

Feature request

We need to create an end point on our API to allow user information sharing between Slack OAuth and OC user profiles.
We want a database of user information for our own purposes (like user management.)

Proposed solution

We need the end point created.

Additional context

This issue is related to #345

[jasonappah]

I noticed #345 was closed. Is this still something you all need? If so, I don't think it should be too hard to pull data from Slack, and I'm pretty sure we can use their Events API to subscribe to any changes in user data.