Bump petgraph from 0.6.0 to 0.6.2
Bump petgraph from 0.6.0 to 0.6.2

Bumps [petgraph](https://github.com/petgraph/petgraph) from 0.6.0 to 0.6.2.
- [Release notes](https://github.com/petgraph/petgraph/releases)
- [Changelog](https://github.com/petgraph/petgraph/blob/master/RELEASES.rst)
- [Commits](https://github.com/petgraph/petgraph/commits)

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

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
habitat-sh/habitat,habitat-sh/habitat,habitat-sh/habitat,habitat-sh/habitat,habitat-sh/habitat,habitat-sh/habitat,habitat-sh/habitat,habitat-sh/habitat