Update reqwest to 0.12

[russellbanks]

Update reqwest to 0.12

[obmarg]

There are things I'm considering to make this less of an issue in the meantime though. Either:

1. I could probably add reqwest version specific features. Like if reqwest 0.13 came out next week maybe I'd add that as a separate reqwest-13 feature rather than just breaking everything.
2. I have also been considering moving the http integrations out of cynic and into a separate library. I'd maybe be less hesitant to bump the major version of that theoretical library when faced with a reqwest version bump, since it'd be closer to the core of the library.

Can't guarantee 2 will happen anytime soon - but I'll at least try to remember 1 next time there's a reqwest bump.

[obmarg]

Unfortunate limitation of 0.x versions this. I'll upgrade when I get a minute, should be easy.

Though you're welcome to make a PR in the meantime if you're up for it.

[amnn]

Heads up -- I ran into an issue where the same code seemed to hit this issue (run_graphql method not found in 'RequestBuilder') in one project, but not in another, and it was due to this change by introduced as part of a patch release of cynic.

If you have a Cargo.toml like this:

[dependencies]
cynic = { version = "3.4.3", features = ["http-reqwest"] }
reqwest = "0.11"

and a lock file is generated from it prior to this change, then it will continue to work after #875 lands, because cynic has been resolved to 3.4.3 and won't pick up the bump to cynic's dependency on reqwest.

If I use the same set of dependencies in a new project, it will fail because the version bound on cynic will be resolved to 3.7.3 implicitly on lock file generation (including #875), while the same thing doesn't happen to the patch version of reqwest because it's pre 1.0.

It seems like the version bump on reqwest should be treated as a breaking change (gated by a major version bump) for cynic?

[obmarg]

Yeah, sorry for the hassle @amnn - but my policy is generally to do a minor bump when bumping public dependencies by a minor version.

Which is what happened - this was released in 3.5.0 not a patch release.

I can see the argument for it being a breaking change, but I'm not really happy tying my major versions into the minor versions of an optional dependency. Hopefully reqwest hits v1 sometime and this might become less of a problem.

[amnn]

No worries, either of those options seem reasonable to me -- main thing is avoiding the confusing interaction between Cargo's default behaviour in accepting patch/minor bumps and the implications of a minor bump on a pre-1.0 version!