chore(deps): bump acorn from 6.3.0 to 6.4.1 (#291)

Bumps [acorn](https://github.com/acornjs/acorn) from 6.3.0 to 6.4.1.
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](acornjs/acorn@6.3.0...6.4.1)

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

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