Created Sherman Morrison method (#1162)
Created Sherman Morrison method (#1162)

* Created Sherman Morrison

* Added docstring for class

* Updated Sherman morrison

1. Added docstring tests
2. Tweaked __str__() using join
3. Added __repr__()
4. Changed index validation to be independent method

* Applied cclauss's point

1. Reduced line length for __str__()
2. Removed parens for assert

TheAlgorithms/Python