Remove additional dependencies for Hetzner. (#502)
Remove additional dependencies for Hetzner. (#502)

As the old Hetzner integration was removed we don't need these
dependencies anymore. The new dns.hetzner.com integration only uses
common dependencies.

This change removes dependency on dnspython and html5lib, whereas
beautifulsoup is still used by other integrations.
AnalogJ/lexicon,AnalogJ/lexicon