Update dependencies and Go version (#12)

- Bump Go version to 1.19
- Update libdns to v1.1.1
- Update go.uber.org/multierr to v1.11.0

Fix zone detection for subdomain DNS record management (#11)

Resolves a bug where DirectAdmin provider attempted to create DNS
records in non-existent zones for subdomain requests. For example, when
managing host.subdomain.domain.com, the provider incorrectly tried to
use zone subdomain.domain.com instead of the actual managed zone domain.com.

Key changes:
- Add findManageableZone() with parent zone traversal algorithm
- Add getDomainList() to retrieve available DirectAdmin domains
- Add adjustRecordForZone() for proper subdomain record name handling
- Update all CRUD operations to use detected manageable zones
- Add comprehensive test coverage for zone detection scenarios
- Add LIBDNS_DA_NON_ROOT_TEST_ZONE environment variable for testing

This fix enables proper ACME challenge handling for subdomains in Caddy
server deployments, resolving "Domain does not belong to you" errors.

Update to use libdns 1.x (#8)

Migrate to libdns v1.1.0

- Update libdns dependency to v1.1.0
- Replace libdns.Record with specific record types
- Implement new SetRecords atomicity semantics
- Update tests for new API

Fix root zone bug and add tests (#4)

chore: update to libdns/libdns v0.2.2 - fix build errors with caddy v…

…2.8.0+ (#3)

* chore: update to libdns/libdns v0.2.2

* cleanup: fix build error with libdns v0.2.2

Implement insecure requests functionality (#2)

Fix trailing dot bug (#1)

* Fixed zone trailing '.' bug
* Add much more useful debug logging
* Refactored request execution
* Added zone trailing '.' test

Update package paths