Minor - v0.1.5

This is a minor change:

1. Add unit tests. The current test coverage is 100%;
2. Add Makefile, for better testing;
3. Update README;
4. Add GitHub workflows.

Refactor and update license.

Merge pull request #3 from txaty/generics

Refactor, update License.

Async method and invalid number handling

Merge pull request #2 from txaty/generics

Add async methods and invalid number handling

Generics

v0.1.2

Update README.md

Submit and Map methods

v0.1.1

Submit and Map methods.