Updated dependencies

[AlexSherbinin]

Updated dependencies, added rust-toolchain.toml file with nightly channel described.

[S0c5]

@Fishrock123 is there an interest in merging this PR? We're facing issues with nested dependencies that are outdated and are breaking our apps

[Fishrock123]

I will take a dependency upgrade that does not cause a major version (is not a breaking change for exposed interfaces)

I will take an update to tokio/hyper and request/curl only if those updates include it under a separate feature flag, with the dependency version in the flag, which was the big mistake here all along.

in more clear terms, the hyperium_http feature should have been hyperium_http_02 (the 0.2 version), so for hyper http 1.0 it should be hyperium_http_1