As .env.* is added to the .gitignore, anyone who wishes to clone this repo will not have access to the necessary environment variables.
You will need to create two .env files for your project: .env.test and .env.development. In .env.test add PGDATABASE=nc_news_test into the file and in .env.development add PGDATABASE=nc_news_test. With the correct database name for that environment (see /db/setup.sql for the database names). If you need any help, please reference documentation