new helpers to update read model [redis_readmodel_client]

Author: hjwp

src/allocation/adapters/redis_eventpublisher.py

@@ -14,3 +14,11 @@
 def publish(channel, event: events.Event):
     logging.debug("publishing: channel=%s, event=%s", channel, event)
     r.publish(channel, json.dumps(asdict(event)))
+
+
+def update_readmodel(orderid, sku, batchref):
+    r.hset(orderid, sku, batchref)
+
+
+def get_readmodel(orderid):
+    return r.hgetall(orderid)