Changes

Summary

1. Add sharded listener provider (#595) (commit: 0befe74) (details)

Commit 0befe74cb907609ffe8ec442f7a04b622803a59d by Florian Spieß Add sharded listener provider (#595) (commit: 0befe74)
	src/main/java/net/dv8tion/jda/bot/sharding/DefaultShardManager.java (diff)
	src/main/java/net/dv8tion/jda/bot/sharding/DefaultShardManagerBuilder.java (diff)
	src/main/java/net/dv8tion/jda/bot/sharding/ShardManager.java (diff)