Quality: Tests for CI

[jinningwang]

Create code tests to ensure the code quality.
For now, we can cover the python code part first, such as the independent data reader and the backend framework.

Additionally, some GitHub actions can be added to alleviate manual efforts. Such as actions to automatically publish to PyPi and Conda.

Reference:
ANDES code test
ANDES GiiHub workflow
pytest
CI/CD in software development

[jinningwang]

Close as Zack solved this.