Update bindgen requirement from 0.51 to 0.52 (#57)

Updates the requirements on [bindgen](https://github.com/rust-lang/rust-bindgen) to permit the latest version.
- [Release notes](https://github.com/rust-lang/rust-bindgen/releases)
- [Changelog](https://github.com/rust-lang/rust-bindgen/blob/master/CHANGELOG.md)
- [Commits](rust-lang/rust-bindgen@v0.51.0...v0.52.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

Cargo.toml

@@ -25,7 +25,7 @@ num-traits = "^0.2"
 #failure = "0.1"
 
 [build-dependencies]
-bindgen = "0.51"
+bindgen = "0.52"
 cc = "1.0"
 
 [features]