chore(database): setup and configure postgres database

- install and configure pg to export two pools
- add normal database and test database urls to .env
- create database schema
- setup npm scripts to manage database

[Finishes #160819060]

.env.example

@@ -0,0 +1,3 @@
+PORT=[server_port_number]
+DATABASE_URL=postgres://[username]@[server]:[port]/[database_name]
+TEST_DATABASE_URL=postgres://[username]@[server]:[port]/[database_name]

package.json

@@ -6,9 +6,13 @@
   "scripts": {
     "start": "npm run build && node ./dist/index.js",
     "build": "babel ./server -d dist",
-    "test": "nyc --reporter=lcov mocha --recursive ./tests/* --require babel-register --exit",
+    "test": "export NODE_ENV=test && nyc --reporter=lcov mocha --recursive ./tests/* --require babel-register --exit",
     "cover": "nyc report --reporter=text-lcov | coveralls",
-    "dev": "nodemon --exec babel-node ./server/index.js"
+    "dev": "nodemon --exec babel-node ./server/index.js",
+    "purge-db": "echo 'DROP DATABASE IF EXISTS fastfoodfast;' | psql -U postgres && echo 'CREATE DATABASE fastfoodfast;' | psql -U postgres",
+    "setup-schema": "psql -U postgres fastfoodfast < ./server/db/schema.sql",
+    "config-db": "npm run purge-db && npm run setup-schema",
+    "setup-testdb": "echo 'DROP DATABASE IF EXISTS fastfoodfast_test;' | psql -U postgres && echo 'CREATE DATABASE fastfoodfast_test;' | psql -U postgres"
   },
   "engines": {
     "node": "8.12.0"
@@ -24,12 +28,13 @@
   },
   "homepage": "https://github.com/akhilome/fast-food-fast#readme",
   "dependencies": {
+    "babel-cli": "^6.26.0",
+    "babel-preset-env": "^1.7.0",
+    "babel-preset-stage-2": "^6.24.1",
     "body-parser": "^1.18.3",
     "dotenv": "^6.0.0",
     "express": "^4.16.3",
-    "babel-cli": "^6.26.0",
-    "babel-preset-env": "^1.7.0",
-    "babel-preset-stage-2": "^6.24.1"
+    "pg": "^7.4.3"
   },
   "devDependencies": {
     "chai": "^4.1.2",

server/db/config.js

@@ -0,0 +1,16 @@
+import dotenv from 'dotenv';
+import { Pool } from 'pg';
+
+dotenv.config();
+
+const env = process.env.NODE_ENV || 'development';
+let pool;
+let testPool;
+
+if (env === 'test') {
+  testPool = new Pool({ connectionString: process.env.TEST_DATABASE_URL });
+} else {
+  pool = new Pool({ connectionString: process.env.DATABASE_URL });
+}
+
+export default { pool, testPool };

server/db/schema.sql

@@ -0,0 +1,21 @@
+CREATE TABLE IF NOT EXISTS users (
+  id serial PRIMARY KEY,
+  name VARCHAR(50) NOT NULL,
+  email VARCHAR(50) NOT NULL,
+  password VARCHAR(255) NOT NULL,
+  is_admin BOOLEAN NOT NULL
+);
+
+CREATE TABLE IF NOT EXISTS menu (
+  id serial PRIMARY KEY,
+  food_name VARCHAR(255) NOT NULL,
+  price REAL NOT NULL
+);
+
+CREATE TABLE IF NOT EXISTS orders (
+  id serial PRIMARY KEY,
+  item INTEGER REFERENCES menu(id),
+  author INTEGER REFERENCES users(id),
+  date DATE NOT NULL DEFAULT CURRENT_DATE,
+  status VARCHAR(50) NOT NULL DEFAULT 'new'
+);