0.20.3

Hackathon/hotfixes (#413)

* fix save results

* empty programs hotfix

* clean sequenes

* circuit_to_pulses fix

* black formatting

* unittest for execute

* updated changelog

* black formatting

* changelog updated

* isort test

* cleaning unittest

* black reformat

* fixing unittest for mocking all functions called

* another fix

* add save_results flag

* fix

* fix tests

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Co-authored-by: AlbertMitjans <a.mitjanscoma@gmail.com>