update dependencies

• refactor: mark property initial value as undefined 2b101ff
• chore: update dependencies 47a225d
• ci: use cross-env for setting the environment variables a6da01c
• improvement: update provider stub 843c599
• ci: remove appveyor in favor of gh actions 65f3085
• chore: update dependencies 69f75ed

v5.3.0...v5.3.1