The examples in the test folder are not working

[thomaslettau]

The file test_imaging.py works as expected, but if I execute the other files, I get various AttributeErrors.

test_free_space_prop.py

AttributeError: module 'pyoptics.propagators' has no attribute 'prop_free_space'

test_wpm.py

ModuleNotFoundError: No module named 'numexpr'

test_propagators.py

If I change plot_image to plot_intensity and the arguments of grid1d from a tuple to single arguments, I still get:
ModuleNotFoundError: No module named 'numexpr'