Version 0.9.0

This is mostly a supporting release with several new features
and lots of bug fixes.

Features

• Forbids to use magic module methods __getattr__ and __dir__
• Forbids to use multiline conditions
• Forbids local variables that are only used in return statements

Bugfixes

• Fixes module names for modules like io.py
• Fixes false positive Z310 for numbers like 0xE
• Fixes false positive for compare ordering with await
• Fixes problem with missing _allowed_left_nodes
• Fixes problem false positive for Z121 when using _ for unused var names
• Fixes false positive for negative number in default values
• Fixes error text for ComplexDefaultValuesViolation
• Fixes problem with false positive for Z459
  when a default value is an Ellipsis

Misc

• Adds py.typed file in case someone will import our code,
  now it will have types
• Adds several missing @final decorators
• Enforces typing support
• Refactors how typing_extensions package is used
• Adds docs about black
• Adds big "Star" button
• Multiple dependencies update
• Better exclude rule for flake8 check
• Removed warnings from pytest