setup integration test

node_modules/bottleneck/src/redis/register_client.lua

@@ -0,0 +1,12 @@
+local queued = tonumber(ARGV[num_static_argv + 1])
+
+-- Could have been re-registered concurrently
+if not redis.call('zscore', client_last_seen_key, client) then
+  redis.call('zadd', client_running_key, 0, client)
+  redis.call('hset', client_num_queued_key, client, queued)
+  redis.call('zadd', client_last_registered_key, 0, client)
+end
+
+redis.call('zadd', client_last_seen_key, now, client)
+
+return {}