⬆️ Update reqwest requirement from 0.8 to 0.9

Updates the requirements on [reqwest](https://github.com/seanmonstar/reqwest) to permit the latest version.
- [Release notes](https://github.com/seanmonstar/reqwest/releases)
- [Changelog](https://github.com/seanmonstar/reqwest/blob/master/CHANGELOG.md)
- [Commits](https://github.com/seanmonstar/reqwest/commits/v0.9.0)

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

Cargo.toml

@@ -15,7 +15,7 @@ build = "build.rs"
 travis-ci = { repository = "mockersf/jenkins-api.rs" }
 
 [dependencies]
-reqwest = "0.8"
+reqwest = "0.9"
 hyper = "0.11"
 
 serde = "1.0"