message: implement suscription
diff: -import { RequestPolicy, OperationContext, createRequest } from 'urql/core';
  -import { pipe, subscribe } from 'wonka';
  +import { OperationContext, createRequest } from 'urql/core';
  import { DocumentNode } from 'graphql';
  -import { observe } from 'svelte-observable';
  import { getClient } from '../context';
  +import { observe } from './observe';
  export interface SubscriptionArguments<Variables> {
  query: DocumentNode | string;
  - variables?: V;
  + variables?: Variables;
  pause?: boolean;
  context?: Partial<OperationContext>;
  }
  export const subscribe = <Variables = object>(
  - args: QueryArguments<Variables>
  + args: SubscriptionArguments<Variables>
  ) => {
  const client = getClient();
  const request = createRequest(args.query, args.variables as any);
  - const observable = pipe(
  - client.executeSubscription(request, args.context),
  - subscribe(arg => arg)
  - );
  -
  - return observe(observable);
  + return observe(client.executeSubscription(request, args.context));
  };
  