build(deps): bump once_cell from 1.4.0 to 1.7.2 (#46)

Bumps [once_cell](https://github.com/matklad/once_cell) from 1.4.0 to 1.7.2.
- [Release notes](https://github.com/matklad/once_cell/releases)
- [Changelog](https://github.com/matklad/once_cell/blob/master/CHANGELOG.md)
- [Commits](matklad/once_cell@v1.4.0...v1.7.2)

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Cargo.toml

@@ -20,7 +20,7 @@ dialoguer = "0.6.2"
 edit = "0.1.2"
 git2 = "0.13.6"
 itertools = "0.9.0"
-once_cell = "1.4.0"
+once_cell = "1.7.2"
 serde = { version = "1.0.114", features = ["derive"] }
 
 [package.metadata.commits]