Update logos requirement from 0.14.0 to 0.15.0

Updates the requirements on [logos](https://github.com/maciejhirsz/logos) to permit the latest version.
- [Release notes](https://github.com/maciejhirsz/logos/releases)
- [Changelog](https://github.com/maciejhirsz/logos/blob/master/RELEASE-PROCESS.md)
- [Commits](maciejhirsz/logos@v0.14...v0.15)

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

Signed-off-by: dependabot[bot] <[email protected]>

Cargo.toml

@@ -14,7 +14,7 @@ path = "tests/lib.rs"
 [dependencies]
 enumn = "0.1.3"
 lazy_static = "1.4.0"
-logos = "0.14.0"
+logos = "0.15.0"
 regex = "1.3"
 thiserror = "1.0"
 serde = { version = "1.0", features = ["derive"] }