Setup Websocket consumers

[tomtitherington]

Background & Context*

Set up a Websocket consumer that upon a successful connection via a client, exposes a "person session".

Goal*

• A client can connect via an "identify" request using their project API key, the person's email and any properties of that person.
• If the connection is successful/accepted then the Websocket server will reply with the "person session" which contains details of their currently active flows.

Implementation Details*

I'm thinking that the "person session" payload should look something like this:

{
  "person_uuid": "string",
  "person_email": "string",
  "active_flows": [
    {
      "flow_instance_uuid": "string",
      "flow_schema_identifier": "string"
    }
  ]
}

Other details can be returned by passing different payloads/parameters within requests to the Websocket. They are not included as part of this piece of work.

Should we be using the Django Channels REST Framework? Will this save us time or make the implementation cleaner?

Acceptance Criteria*

• A client should be able to connect to the endpoint via ws://.
• A client needs to provide their API key and person email for connection to be accepted.
• Upon successful connection, the server should reply with a JSON payload that contains the "person session" (see Implementation Details above).
• A client needs to be able to terminate the session.

Additional Information

• This is just setup work related to the initial connection request and should not include retrieving details about a step, calling a transition for a person .. etc. They will be covered via other issues.

*required field.