Feature requests (Close button, default config, customized html template)

[AnderUstarroz]

This is a great package, but I think there are only few things missing to be outstanding:

• [ ] Close button: adding a close button so users can dismiss the message.
• [ ] Default config: It would be great being able to use a default config rather than having to provide the timeout or class every single time we call the flashmessage().
• [ ] Customized HTML template: Defining our own html template in which the Flash message is displayed would be great.