Log Message:
py-signedjson: updated to 1.1.1

Signedjson 1.1.1

Bugfixes
- Fix incorrect typing annotation for `decode_signing_key_base64`.
- Reinstate `decode_verify_key_base64` function which was erroneously removed in \ 
1.1.0.

Internal Changes
- Use `setuptools_scm` for the version number.