Using github actions to publish to PyPi

[filipecosta90]

This PR simplifies the release using github actions instead of circleci. @gkorland @rafie I've revised this is working as expected on the following dummy project ( it's redistimeseries with a different name only ): https://github.com/filipecosta90/test-release-rts-py With the following release v1.4.7 being published on test.pypi and pypi:

• https://test.pypi.org/project/test-release-rts-py/1.4.7/
• https://pypi.org/project/test-release-rts-py/1.4.7/ . Action that published: https://github.com/filipecosta90/test-release-rts-py/runs/1241437684?check_suite_focus=true