Add Lasse

src/Lasse/__init__.py

src/Lasse/roman_converter_Lasse.py

src/Lasse/string_calculator_Lasse.py

src/my/__init__.py

tests/tests_Lasse/__init__.py

tests/tests_Lasse/report.md

tests/tests_Lasse/test_roman_converter.py

tests/tests_Lasse/test_string_claculator.py