Branch: i30_pythongeometry | Intent: Create module of native Python functions to
	replace numpy functions used in eppy geometry modules
Commit Intent: Create a template function for the cross product (first function
	encountered in surface.py of eppy
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*/eppy/geometry/py_numeric.py
-Added cross function definition with parameters and docstring from numpy's numeric.py...

*eppy/tests/geometry_tests/test_py_numeric.py
-Added a stub test function with docstring to start writing the test prior to
 writing the function itself...
-Removed misplaced function stub with docstring (supposed to be in py_numeric, not test)