Version 1.2.0.

* Converted to Go module.
* Updated .proto files ([#35](#35) by Lucas).
* Updated protobuf dependency.
* Migrated CI to GitHub Actions.

Version 1.1.0.

* Added Decoder.Header() method.
* Added support for non-dense Nodes.
* Minor optimizations.

Merge pull request #21 from qedus/bump-go-versions

Bump Go versions, use latest patch releases