Remove message factory

[joelwurtz]

IMO I don't need it here, the standard (PSR7) is too contraignous to have a very different implementation on the message part (Request / Response) and since we use our own stream (no stream factory needed), using a message factory here is over engineering.

WDYT ? ping @sagikazarmark @dbu @Nyholm

[sagikazarmark]

I would leave it there at least until we see how the PSR MessageFactories end up. Also, I would rather make an overall consensus and this is a BC break.

[Nyholm]

I do not like us to have any dependency on Guzzle.

(except for dev-requirements)

[Nyholm]

I would like to keep the message factories as well. I like the end users to be able to choose what PSR-7 implementation to use. One reason is that Guzzle does not comply with PSR-7 to 100%.

[joelwurtz]

I like the end users to be able to choose what PSR-7 implementation to use. One reason is that Guzzle does not comply with PSR-7 to 100%.

In fact i don't think it matters here, user can still choose it's implementation but it will change anything here.

this is a BC break.

I added a deprecated on the constructor so old way of constructing SocketClient still works

Also i still comply to the contract as i return a object compatible with PSR7.

The only downside of doing this here is someone can have multiple PSR7 implementations in their dependencies, IMO this is something that is affordable in exchange for easier and faster installation / adoption by end-users.

[Nyholm]

This PR has stalled for a year. Both me and Mark are 👎 . All our other clients do follow this pattern.

I will close this. Feel free to open it again if you want continue to discuss it.