v0.4.0

This version introduces PSD2 compatibility and a ready to use product name.

What's Changed

• docs: add new reference docs by @mitch000001 in #26
• chore(go): use go modules by @mitch000001 in #25
• Refactorings by @mitch000001 in #27
• PSD2 compatibility by @mitch000001 in #28

Full Changelog: v0.3.2...v0.4.0