Bump afl from 0.10.1 to 0.12.10

Bumps [afl](https://github.com/rust-fuzz/afl.rs) from 0.10.1 to 0.12.10.
- [Release notes](https://github.com/rust-fuzz/afl.rs/releases)
- [Changelog](https://github.com/rust-fuzz/afl.rs/blob/master/CHANGES.md)
- [Commits](https://github.com/rust-fuzz/afl.rs/commits)

---
updated-dependencies:
- dependency-name: afl
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

Cargo.lock

@@ -22,7 +22,7 @@ structopt = "0.3.21"
 tokio = { version = "1.6.1", features = ["rt"] }
 
 libfuzzer-sys = { version = "0.4.2", optional = true }
-afl = { version = "0.10.1", optional = true }
+afl = { version = "0.12.10", optional = true }
 
 [features]
 default = []