Fixing -spacy install for Preprocessing notebook #1 issue in Tokenanization

[joseaveldanes]

Tokenaziation section has an issue with spacy. Seems like the following works for Mac OS: ! pip install -U spacy

Here's a link to a stackoverflow issue that has different code solutions.

Renata says it might be an environment issue but several participants had this issue too. This solution didn't work for everyone but going into binder seemed to work for now.

@rbarreto