env.js issue

[dvlpr-eth]

Hey, I tried to send pull request but it seems you don't have it enabled, there is issue with env.js. const isDev is missing .env, it prevents Gulp to add sourcemap to css. Ternary operator is missing === 'production'

- export const NODE_ENV = process.env.NODE_ENV ? "production" : "development";
- export const isDev = process.NODE_ENV === "development";
+ export const NODE_ENV = process.env.NODE_ENV === 'production' ? 'production' : 'development';
+ export const isDev = process.env.NODE_ENV === 'development';
export const isProd = process.env.NODE_ENV === 'production';

[YgorNeves]

@hamidnoei do you have any idea how to add react to this boilerplate?