Tests under `expansion_lt/swig/tests/` are overly sensitive

Tests on my machine fails due to numerical differences <10^(-10). I would suggest rounding the numbers in `expansion_lt/swig/tests/output/run_voronotalt_python.py.output.txt` as well as the ones written by `expansion_lt/swig/tests/input/run_voronotalt_python.py` to 10^(-10).