fix link to k-nearest-neighbors code

Merge pull request #87 from cclauss/patch-1

Undefined name: from typing import Dict for line 96

comment out plt.savefig

Merge branch 'master' of https://github.com/joelgrus/data-science-from-scratch

add files for working_with_data

Update README.md

Merge pull request #67 from cenuno/cenuno/ch2

Fix total() so it returns the input xs

Update README.md

Update README.md

Update README.md

Merge pull request #63 from joelgrus/add-license-1

Create LICENSE

Delete LICENSE