chore(deps): bump serde from 1.0.138 to 1.0.139 (#158)

Bumps [serde](https://github.com/serde-rs/serde) from 1.0.138 to 1.0.139.
- [Release notes](https://github.com/serde-rs/serde/releases)
- [Commits](serde-rs/serde@v1.0.138...v1.0.139)

---
updated-dependencies:
- dependency-name: serde
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

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

Cargo.toml

@@ -48,7 +48,7 @@ termcolor = "1.1.3"
 tokio = { version = "1.19.2", features = ["fs", "rt-multi-thread", "signal", "macros"] }
 tokio-rustls = "0.23.4"
 toml = "0.5.9"
-serde = { version = "1.0.138", features = ["derive"] }
+serde = { version = "1.0.139", features = ["derive"] }
 serde_json = "1.0.82"
 structopt = { version = "0.3.26", default-features = false }