Upgrade to new ReactPHP components

[clue]

This component uses deprecated SocketClient which has been replaced by Socket. Also, the HttpClient will be merged into the Http component. Both changes will involve a BC break to our (advanced) API, so I'd like to wait for the ReactPHP component to become more stable for updating this library.

[WyriHaximus]

Are you planning to keep the external API the same?

[clue]

There are currently no plans to change anything about the API except for what needs to be changed, specifically this will mostly involve some minor changes to the namespaces of referenced classes.

[WyriHaximus]

Cool so targeting ^2.0 || ^1.0 should be fully compatible 🎉

[mdrost]

I would love to see some interfaces so I can create for example throttling proxy.

[nick4fake]

@clue, I am not sure about lower bound of package version. While at least, Socket v0.7 should be used due to SocketClient, I've set it to 0.8 as I only tested it agains latest components + I am not sure about lower bounds for other packages

[clue]

Small progress update: I've just released an intermediary v1.2.0 which now supports react/http v0.5 without causing a BC break 🎉 While this doesn't fix this issue completely, this should relax this situation significantly.

I'll release a v1.3.0 shortly which requires this minimum version so we can update the Stream component to v0.6 at least.

The major bump to newest components has to be postponed to the v2.0.0 release because we currently expose a legacy React\SocketClient\ConnectorInterface on our API, which means we have a direct dependency on the deprecated react/socket-client, which does only support react/stream < v0.7.