db created, added tests -- tentative

backend/db/index.js

@@ -0,0 +1,13 @@
+import pg from 'pg';
+
+const pool = new pg.Pool({
+  connectionString: process.env.DATABASE_URL,
+});
+
+export const query = (text, params) => pool.query(text, params);
+
+export const getPool = () => pool;
+
+export const close = () => pool.end();
+
+export default pool;