Include basic condition assignment endpoint about datapipe HOT 1 CLOSED

I think this is working now. Idea is you can make a call like this:

let headersList = {
 "Accept": "*/*",
 "Content-Type": "application/json"
}

let bodyContent = JSON.stringify({
  "experimentID": "rYnzHFJlGyWQ"
});

let response = await fetch("http://127.0.0.1:5001/osf-relay/us-central1/api/condition", { 
  method: "GET",
  body: bodyContent,
  headers: headersList
});

You'll get back a response that has a number between 0 and N-1, where N is the number of conditions in the experiment. The number increments by 1 after each call to the API.

It's going to be a little bit annoying to use this in the context of a jsPsych experiment, because it requires an async wait from the server. Maybe we can add some helper functions to jsPsych to make this easier... 🤔

from datapipe.