Update test-case requirement from 1.1 to 2.0 (#376)

Updates the requirements on [test-case](https://github.com/frondeus/test-case) to permit the latest version.
- [Release notes](https://github.com/frondeus/test-case/releases)
- [Changelog](https://github.com/frondeus/test-case/blob/master/CHANGELOG.md)
- [Commits](frondeus/test-case@v1.1.0...v2.0.0)

---
updated-dependencies:
- dependency-name: test-case
  dependency-type: direct:production
...

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

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

Cargo.toml

@@ -95,7 +95,7 @@ rayon = "1"
 static_assertions = "1.1"
 structopt = "0.3"
 tempfile = "3.1"
-test-case = "1.1"
+test-case = "2.0"
 tracing-subscriber = ">=0.2.12, <0.4.0"
 serde_json = "1"