Secure Server

Notable changes

• + abilities to choose to start http or https or http2 (secure or not) server
• + async init(options): this self-signed-certificate can be generated during runtime if you didn't ask for http with options.selfSigned set to true
• ~ async listen(options): string return url of server
• ~ better api doc (read .d.ts files)

Breaking Changes

• node 12 is required. App class use private field