title: sequalize migration with dotenv
body: <p>I am saving my database config in dotenv file.</p>
  
  <p>I am using sequelize migration which has a config.json file in config folder:</p>
  
  <pre><code>{
   "development": {
      "username": "root",
      "password": null,
      "database": "test",
      "host": "127.0.0.1",
      "dialect": "postgres"
    },
    ....
  }
  </code></pre>
  
  <p>Since I have configuration in dotenv do I have to convert it to js file:</p>
  
  <pre><code>require('dotenv').config({ silent: env === 'production'})
  
  const devConfig = {
    dialect: 'postgres',
    host: process.env.DB_HOST || 'localhost',
    port: process.env.DB_PORT || 5432,
    database: process.env.DB_NAME || '',
    username: process.env.DB_USER || 'postgres',
    password: process.env.DB_PASSWORD || '',
    migrationStorageTableName: 'migrations'
  };
  
  module.exports = {
    development: devConfig,
    production: devConfig
  };
  </code></pre>
  
  <p>but how can I run the the migration, which the config is not JSON?</p>
  
  <pre><code>node_modules/.bin/sequelize db:migrate --config config/config.js
  </code></pre>