⬆️ Update nom requirement from 4.2 to 7.0

Updates the requirements on [nom](https://github.com/Geal/nom) to permit the latest version.
- [Release notes](https://github.com/Geal/nom/releases)
- [Changelog](https://github.com/Geal/nom/blob/master/CHANGELOG.md)
- [Commits](rust-bakery/nom@4.2.0...7.0.0)

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

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

Author: dependabot[bot]

Cargo.toml

@@ -16,7 +16,7 @@ travis-ci = { repository = "mockersf/hocon.rs" }
 
 [dependencies]
 thiserror = "1.0.*"
-nom = "4.2"
+nom = "7.0"
 serde = { version = "1.0", optional = true }
 java-properties = "1.3"
 memchr = "2.3"