Upgrade PSR/http-message

[davidbarratt]

Fixes #249 & #270 & #255

[davidbarratt]

pinging @jacobbednarz !

[jnbn]

Don't know how and why it takes so long to accept a PR in such a big project.

[bserem]

This one needs to be merged!

More and more Drupal sites are using the new version of psr/http-message and Cloudflare can't be installed for them.

[charginghawk]

Running into a dependency conflict with league/oauth2-server requiring psr/http-message ^2.0. Let's get this updated!

[ErgjanJaha]

pinging @jacobbednarz
can we get this done, its been so long

[rghai2005]

@jacobbednarz Any update on this ? I am also getting conflict with league/oauth2-server requiring psr/http-message ^2.0.

[celsoft]

Any update on this ?

[JhordanPG]

Is there any update on this?

[kees-dev]

It would be nice to have this rolling ;-)
in the mean time: https://github.com/kees-dev/cloudflare-php/

[ssicard]

Thanks for your contribution, this fix has been included in the 2.0 release.