Typo in demo & invalid link #25

Typo: pachage -> package

unit03/demo1_glucose.ipynb:

line 15:
"* Fit multiple linear regression models using python's `sklearn` pachage. \n",
should be:
"* Fit multiple linear regression models using python's `sklearn` package. \n",

invalid link

unit03/demo2_python_broadcasting.ipynb:

line 9:
"There is an excellent introduction to `numpy` multi-dimensional arrays on the [scipy](https://docs.scipy.org/doc/numpy-dev/user/quickstart.html) website. In this note, we cover two concepts in a little more detail:\n",

The link for scipy is invalid, and I think the recent one is this: https://docs.scipy.org/doc/numpy/user/quickstart.html