* 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
* chore: Fix examples not working with `cargo run`
## Motivation
PR #991 moved the `tokio` crate to its own subdirectory, but did not
move the `examples` directory into `tokio/examples`. While attempting to
use the examples for testing another change, I noticed that #991 had
broken the ability to use `cargo run`, as the examples were no longer
considered part of a crate that cargo was aware of:
```
tokio on master [$] via 🦀v1.33.0 at ☸️ aks-eliza-dev
➜ cargo run --example chat
error: no example target named `chat`
Did you mean `echo`?
```
## Solution
This branch moves the examples into the `tokio` directory, so cargo is
now once again aware of them:
```
tokio on eliza/fix-examples [$] via 🦀v1.33.0 at ☸️ aks-eliza-dev
➜ cargo run --example chat
Compiling tokio-executor v0.1.7 (/Users/eliza/Code/tokio/tokio-executor)
Compiling tokio-reactor v0.1.9
Compiling tokio-threadpool v0.1.13
Compiling tokio-current-thread v0.1.6
Compiling tokio-timer v0.2.10
Compiling tokio-uds v0.2.5
Compiling tokio-udp v0.1.3
Compiling tokio-tcp v0.1.3
Compiling tokio-fs v0.1.6
Compiling tokio v0.1.18 (/Users/eliza/Code/tokio/tokio)
Finished dev [unoptimized + debuginfo] target(s) in 7.04s
Running `target/debug/examples/chat`
server running on localhost:6142
```
Signed-off-by: Eliza Weisman <[email protected]>
Signed-off-by: Eliza Weisman <[email protected]>
David Kellum