allow activity types

[sKiLdUsT]

This allows for sending activity types described here.

I also included some handy constants to use.

This fixes #146

[landenpls]

It should be noted that the ActivityType enum is discarded in outgoing transport. It is solely for use of incoming messages (e.g. reading friend's activity

From the official docs:

ActivityType is strictly for the purpose of handling events that you receive from Discord; though the SDK/our API will not reject a payload with an ActivityType sent, it will be discarded and will not change anything in the client.

[cpiber]

@afoxie I think you're looking at the wrong docs, if you start from https://discord.com/developers/docs/topics/rpc#setactivity (what is used internally), you land at https://discord.com/developers/docs/topics/gateway#activity-object-activity-types, which doesn't have this restriction.

[Araxeus]

Have any of you even checked to see if this PR works?

this literally doesn't work. first of all

child "activity" fails because [child "type" fails because ["type" must be one of [0, 3]]]

second of all even if you input type 3 it still wont actually do anything...

[Viktova]

PR doesn't work, but this is an issue that needs to be looked into.
@afoxie you're referring to the docs where it says that the type will get discarded whatsoever and the API will not reject the payload, but in the matter of fact, it is rejecting it and returning 400 (Bad Request).

[thehairy]

Suggested change

	exports.ActivityTypes = {
	PLAYING: 0,
	STREAMING: 1,
	LISTENING: 2,
	WATCHING: 3,
	CUSTOM: 4,
	COMPETING: 5
	}
	exports.ActivityTypes = {
	PLAYING: 0,
	WATCHING: 3
	}

Only PLAYING and WATCHING are allowed by RPC. Everything else results in an error.

[sKiLdUsT]

Just to clarify something: This PR was only meant to provide feature-complete integration according to the API docs (https://discord.com/developers/docs/topics/gateway-events#activity-object-activity-types), assuming in the future the use of these constants would open up to the public. I'm aware it's not working right now (since there is no public access to most of the constants) and I'm willing to close this request if there's no need for it.