If you don't have Postgres on your computer run
brew install postgres
Run npm install and then run:
npm install -g knex
Then start your database and run:
postgres -D /usr/local/var/postgres
createdb yumsnap
knex migrate:latest
knex seed:run
Do not CTRL-C to stop Postgres To stop your database:
pg_ctl -D /usr/local/var/postgres stop -s -m fast