Update http requirement from 0.1 to 0.2

Updates the requirements on [http](https://github.com/hyperium/http) to permit the latest version.
- [Release notes](https://github.com/hyperium/http/releases)
- [Changelog](https://github.com/hyperium/http/blob/master/CHANGELOG.md)
- [Commits](hyperium/http@v0.1.0...v0.2.0)

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

http-zipkin/Cargo.toml

@@ -11,5 +11,5 @@ categories = ["web-programming"]
 keywords = ["zipkin", "tracing"]
 
 [dependencies]
-http = "0.1"
+http = "0.2"
 zipkin = { version = "0.4", path = "../zipkin" }