[Python] Release 0.22.0

Changed

• Extend email validation. #471

Fixed

• time format validation (leap seconds and second fractions).
• duration format validation.
• Panic on the root $id without a base. #547
• hostname format validation (double dot).
• idn-hostname format validation. #101

Performance

• Faster building of a validator.
• hostname, date, time, date-time, and duration formats validation.
• Cache regular expressions for pattern. #417