chore(deps): allow psr/http-message v2

[simPod]

No description provided.

[nicolas-grekas]

In the CI:

• Locking psr/http-message (1.1)

So that's not enough.

Also, is this lib really compatible with v2? Doesn't it miss some return types?

[simPod]

Hm, let's test it.

[simPod]

There are indeed some type changes required but I believe the v2 support won't be possible now since old php versions are allowed.

[nicolas-grekas]

We should bump to PHP >=7.2 also

[simPod]

If that's okay with you I've opened >=7.2 PR here #226

[simPod]

Also, I think we cannot have support for both v1 and v2 since methods with typed arguments are not backward compatible.

[nicolas-grekas]

methods with typed arguments are not backward compatible

because of the behavior change when passing incompatible types, or?

[simPod]

Because changing e.g.

-     public function withProtocolVersion($version): self
+     public function withProtocolVersion(string $version): self

is required and compatible with v2 but not compatible with v1

[nicolas-grekas]

It's compatible with 1.1, so we could just bump to ^1.1|^2.0, no?

[simPod]

Test suite is being adapted here php-http/psr7-integration-tests#68

[nicolas-grekas]

Closing in favor of #234, thanks for pushing for this.