black formatting

binarycpython/tests/test_distributions.py

binarycpython/tests/test_functions.py

binarycpython/tests/test_grid.py

binarycpython/tests/test_grid_options_defaults.py

binarycpython/tests/test_plot_functions.py

binarycpython/tests/test_stellar_types.py

binarycpython/tests/test_useful_funcs.py

binarycpython/utils/functions.py

binarycpython/utils/grid.py

binarycpython/utils/useful_funcs.py

docs/source/conf.py

examples/examples.py

setup.py