Bump tokio from 1.19.2 to 1.20.0

Bumps [tokio](https://github.com/tokio-rs/tokio) from 1.19.2 to 1.20.0.
- [Release notes](https://github.com/tokio-rs/tokio/releases)
- [Commits](https://github.com/tokio-rs/tokio/compare/tokio-1.19.2...tokio-1.20.0)

---
updated-dependencies:
- dependency-name: tokio
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.lock

@@ -1497,10 +1497,11 @@ checksum = "cda74da7e1a664f795bb1f8a87ec406fb89a02522cf6e50620d016add6dbbf5c"
 
 [[package]]
 name = "tokio"
-version = "1.19.2"
+version = "1.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c51a52ed6686dd62c320f9b89299e9dfb46f730c7a48e635c19f21d116cb1439"
+checksum = "57aec3cfa4c296db7255446efb4928a6be304b431a806216105542a67b6ca82e"
 dependencies = [
+ "autocfg",
  "bytes",
  "libc",
  "memchr",