Go Common Packages

• dotenv - Loads env vars from a .env file or custom files.
• errorx - Error extension with code and message.
• httpclient - HTTP client containing raw Client, BytesClient and ObjectClient.
• mail - Simple mail client.
• notify - Notification interface, supports template, filter, tingtalk and mail.
• validator - Used for parameter validation.
• response - Standard response.
• middleware - some useful middlewares.