Mac OSX ships with python (2) and python3 with pip3.
They should be current enough versions. If not, you can update them.
pip3 install -U pip3 setuptools
First install spaCy
pip3 install -U spacy
Then install the language pack
python3 -m spacy download en_core_web_md
Last install our libraries
pip3 install -r requirements.txt
Now you can run your app
python3 app.py