MKS_code_tests

This function has a few tests to make sure that functions MS and MSf are
working correctly.
MS.py

This is a .py version of the MS function. ipynb files can load code from
other notebooks. All the functions that are uploaded from now should be
.py files.
MSf - Microstructure Function

This function takes in an Eigen microstructure function and returns the
corresponding microstructure function.
MS  - Fixed Spelling Error in function comments

Fixed eigen to Eigen