Version 0.1.0

• Transfer code from remark42
• Changed to be more generic, without any application-specific properties and checks
• User struct simplified and extended with attributes
• Added claim updater to customize token on the caller side
• Added verification interface to implemented custom filtering of tokens
• Secret management moved to its own interface
• Added top-level auth service wiring all parts together
• Logging changed. By default prints nothing and accept a simple logger interface