Install postgres (on Mac you can use Postgres.app) Install npm and node.js (https://nodejs.org/en/)
Run these commands:
npm install -g knex
npm install
npm start
createdb power_ballot_development
knex migrate:latest
node server/update_data.js
node server/insert_candidate_metadata.js
heroku pg:push power_ballot_development DATABASE_URL --app power-ballot