Hetzner API DynDNS v1.3

In version 1.3 several dependencies have been removed so that the script can be used on multiple systems, including OpenWRT.
In addition the own lookup service from Hetzer ip.hetzner.com is now used to determine the IP.

Many thanks to @thcrt for these changes.

What's Changed

• Remove unneeded dependencies by @thcrt in #35

New Contributors

• @e1mo made their first contribution in #28
• @thcrt made their first contribution in #35

Full Changelog: v1.2...v1.3