v1.0.0

O que mudou

Ajustes para openboleto rodar em ambientes com PHP 7.3

fix: ajustando composer pra ficar compativel com php 7.3
feat: add Dockerfile and docker-compose for PHP 7.3 environment setup
Update README.md
feat: update CI workflow for PHP 7.3 environment (Todos testes feitos no ambiente usando PHP 7.3)

Full Changelog: https://github.com/Danielopes7/openboleto/commits/v1.0.0