Async support

[ramnes]

Hey there, thanks for the neat library.

Do you have any plan to support native async features of Python for the client?

e.g. something in the lines of:

import asyncio
import random

from recombee_api_client.api_client import AsyncRecombeeClient, Region
from recombee_api_client.exceptions import APIException
from recombee_api_client.api_requests import *

async def main():
    client = AsyncRecombeeClient('--my-database-id--', '--db-private-token--', region=Region.US_WEST)
    
    #Generate some random purchases of items by users
    PROBABILITY_PURCHASED = 0.1
    NUM = 100
    purchase_requests = []
    
    for user_id in ["user-%s" % i for i in range(NUM) ]:
      for item_id in ["item-%s" % i for i in range(NUM) ]:
        if random.random() < PROBABILITY_PURCHASED:
    
          request = AddPurchase(user_id, item_id, cascade_create=True)
          purchase_requests.append(request)
    
    try:
        # Send the data to Recombee, use Batch for faster processing of larger data
        print('Send purchases')
        await client.send(Batch(purchase_requests))
    
        # Get recommendations for user 'user-25'
        response = await client.send(RecommendItemsToUser('user-25', 5))
        print("Recommended items: %s" % response)
    
        # User scrolled down - get next 3 recommended items
        response = await client.send(RecommendNextItems(response['recommId'], 3))
        print("Next recommended items: %s" % response)
    
    except APIException as e:
        print(e)


asyncio.run(main())