falsify_graph uses np.math which does not exist

[samiislam]

Describe the bug
On line 935

dowhy/dowhy/gcm/falsify.py

Line 935 in e79d012

self.max_perms = np.math.factorial(self.causal_graph.number_of_nodes()) - int(self.exclude_original_order)

the method falsify_graph uses np.math which does not work.

Steps to reproduce the behavior

1. Use falsify_graph in some code with valid parameters
2. Errors out: AttributeError: module 'numpy' has no attribute 'math'

Expected behavior
falsify_graph returns without error

Version information:

• DoWhy version 0.11.1

[bloebp]

Hey, can you check which numpy version you have? That might be outdated.

[bloebp]

Regardless, addressed it here: #1273