2.1 (2020-08-19)

• Treat getattr/hasattr(obj, "constant_string", ...) as a reference to
  obj.constant_string (jingw, #219).
• Fix false positives when assigning to x.some_name but reading via
  some_name, at the cost of potential false negatives (jingw, #221).
• Allow reading options from pyproject.toml (Michel Albert, #164, #215).