build(deps): bump log from 0.4.21 to 0.4.22

Bumps [log](https://github.com/rust-lang/log) from 0.4.21 to 0.4.22.
- [Release notes](https://github.com/rust-lang/log/releases)
- [Changelog](https://github.com/rust-lang/log/blob/master/CHANGELOG.md)
- [Commits](rust-lang/log@0.4.21...0.4.22)

---
updated-dependencies:
- dependency-name: log
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Cargo.toml

@@ -8,7 +8,7 @@ readme = "README.md"
 repository = "https://github.com/wathiede/pbrt"
 version = "0.1.6-alpha.0"
 [dependencies]
-log = "0.4.21"
+log = "0.4.22"
 image = "0.25.1"
 regex = "1.10.4"
 structopt = "0.3.26"