* use dyn Trait syntax where appropriate
recent rust nightly started warning that not using `dyn` was
deprecated. This requires MSRV 1.27.0+.
* rustfmt fallout from dyn additions
* stop explicit allow of rust_2018_idioms
* more dyn Trait syntax
* drop tokio-macros from 0.1.x workspace
Since tokio-macros specifies an edition=2018, we would otherwise
require MSRV 1.31.0 to build/test it. And tokio-macros isn't used with
tokio 0.1.x.
* reactor: narrow tokio-io-pool dev dep to 0.1.4
Since 0.1.5-6 is now a edition=2018 crate, which has effective MSRV
1.31.0.
* narrow tempfile dev-dep to avoid MSRV bump
tempfile 3.1.0 pulls in rand 0.7.0 and is MSRV 1.32.0
* narrow flate2 dev-dep to avoid MSRV bump
flate2 1.0.10-11 have MSRV 1.34.0.
github refs: alexcrichton/flate2-rs#207
* fs: drop deprecated tempdir crate use in tests
In particular because it pulls in old rand duplicates. Replace use
with tempfile::tempdir() which has been available since tempfile
3.0.0.
backport-of: #1312
* increase CI MSRV to 1.28.0
This change adds an extension trait to `BufStream` and puts the core
trait behind a feature flag for optional use.
This mainly adds the additional functions in an extension trait to
allow the user to select if they want just the core trait or the fully
featured version. Now the user can add the core feature to _not_
include the extension trait. By deafult, this feature is disabled.