Bump bifurcan from 0.2.0-alpha4 to 0.2.0-alpha6
Bump bifurcan from 0.2.0-alpha4 to 0.2.0-alpha6

Bumps [bifurcan](https://github.com/lacuna/bifurcan) from 0.2.0-alpha4 to 0.2.0-alpha6.
- [Release notes](https://github.com/lacuna/bifurcan/releases)
- [Changelog](https://github.com/lacuna/bifurcan/blob/master/CHANGELOG.md)
- [Commits](https://github.com/lacuna/bifurcan/compare/0.2.0-alpha4...0.2.0-alpha6)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
dizzzz/exist,wolfgangmm/exist,eXist-db/exist,windauer/exist,dizzzz/exist,eXist-db/exist,windauer/exist,wolfgangmm/exist,wolfgangmm/exist,lcahlander/exist,dizzzz/exist,wolfgangmm/exist,dizzzz/exist,eXist-db/exist,eXist-db/exist,wolfgangmm/exist,dizzzz/exist,adamretter/exist,windauer/exist,wolfgangmm/exist,windauer/exist,lcahlander/exist,eXist-db/exist,lcahlander/exist,dizzzz/exist,windauer/exist,adamretter/exist,adamretter/exist,adamretter/exist,adamretter/exist,eXist-db/exist,lcahlander/exist,windauer/exist,lcahlander/exist,adamretter/exist,lcahlander/exist