Update toml requirement from 0.7 to 0.8 (#337)

Updates the requirements on [toml](https://github.com/toml-rs/toml) to permit the latest version.
- [Commits](toml-rs/toml@toml-v0.7.0...toml-v0.8.0)

---
updated-dependencies:
- dependency-name: toml
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Cargo.toml

@@ -69,7 +69,7 @@ raft = { git = "https://github.com/tikv/raft-rs", branch = "master", default-fea
 rand = "0.8"
 rand_distr = "0.4"
 tempfile = "3.6"
-toml = "0.7"
+toml = "0.8"
 
 [features]
 default = ["internals", "scripting"]