Update humantime requirement from 1.2.0 to 2.0.0

Updates the requirements on [humantime](https://github.com/tailhook/humantime) to permit the latest version.
- [Release notes](https://github.com/tailhook/humantime/releases)
- [Commits](tailhook/humantime@v1.2.0...v2.0.0)

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

Cargo.toml

@@ -38,7 +38,7 @@ git2-curl = "0.12.0"
 glob = "0.3.0"
 hex = "0.4"
 home = "0.5"
-humantime = "1.2.0"
+humantime = "2.0.0"
 ignore = "0.4.7"
 lazy_static = "1.2.0"
 jobserver = "0.1.13"