better config implementation from ENV or json file.

using new environment;
params passed as docker-compose params

models/index.js

@@ -5,6 +5,7 @@ const path = require('path');
 const Sequelize = require('sequelize');
 const basename = path.basename(__filename);
 const env = process.env.NODE_ENV || 'development';
+console.log("ENV: %s", env);
 const config = require(__dirname + '/../config/config.json')[env];
 const db = {};
 
@@ -12,6 +13,7 @@ let sequelize;
 if (config.use_env_variable) {
   sequelize = new Sequelize(process.env[config.use_env_variable], config);
 } else {
+  console.log("Sequelize: using config.json configuration.");
   sequelize = new Sequelize(config.database, config.username, config.password, config);
 }