running on a mac:
sudo easy_install pip
sudo pip install virtualenv
virtualenv scrapy
activate the virtualenv (navigate to where your virtualenv is, usually ~/.virtualenvs/<name_of_virtualenv>
source bin/activate
git clone https://github.com/mancdaz/scrapy-heaver/
cd scrapy-heaver
pip install -r requirements.txt
scrapy crawl snickers -o snickers.json
scrapy crawl snickers -o snickers.csv
<lots of output>