The psr/http-message v2 is not supported

[SergeC]

The psr/http-message v2 is not supported. Please add support,

Downgrading psr/http-message (2.0 => 1.1)

[SimonFrings]

@SergeC I opened a ticket to add support for psr/http-message v2 in #513. This ticket should include all necessary information for the v2 upgrade. As also mentioned in said ticket, we first need to remove our dependency on ringcentral/psr7, otherwise we can't be compatible with psr/http-message v2.

Additionally, I think this ticket here is more of a feature request instead a bug. We recommend opening bug tickets only when you can provide evidence of something being broken, just as a friendly reminder for future tickets :)

I believe this should answer everything in here, so I will close this ticket. Further discussion will happen in #513.