Begin adding support for PostgreSQL database storage

database/database.js

@@ -0,0 +1,9 @@
+const app = require('../app');
+const { Client } = require('pg');
+
+if (process.env.NODE_ENV !== 'production' || process.env.NODE_ENV !== 'testing') {
+  require('dotenv').config();
+}
+
+const client = new Client();
+client.connect();