Update itertools requirement from 0.11.0 to 0.12.0

Updates the requirements on [itertools](https://github.com/rust-itertools/itertools) to permit the latest version.
- [Changelog](https://github.com/rust-itertools/itertools/blob/master/CHANGELOG.md)
- [Commits](rust-itertools/itertools@v0.11.0...v0.12.0)

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

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

Cargo.toml

@@ -24,7 +24,7 @@ cfg-if = "1.0.0"
 crc32fast = {version = "1.2.1", optional = true}
 digest = {version = "0.10.3", optional = true}
 flate2 = {version = "1.0.19", optional = true}
-itertools = "0.11.0"
+itertools = "0.12.0"
 md-5 = {version = "0.10.1", optional = true}
 sha-1 = {version = "0.10.0", optional = true}
 sha2 = {version = "0.10.2", optional = true}