chore: bump version after release

build: make dependency on Click optional

build: remove dependency on attrs

fix: typo in changelog

style: fix typing errors

build: re-add `shamir` cli tool to build script

feat: Support extendable backup flag.

feat: Add BIP32 master extended private key to test vectors.

build: Switch to poetry. Bump version.

update changelog, bump version

Linting with flake8

Introducing Github actions

bump version to re-release the correct files on pypi

add changelog

Improve error handling of mismatching shares.