Bump version and update CHANGELOG

Author: lafrech

CHANGELOG.rst

@@ -1,6 +1,17 @@
 Changelog
 ---------
 
+6.0.0b1 (2022-10-04)
+********************
+
+Features:
+
+- Add ``OpenAPIConverter.add_parameter_attribute_function`` to allow
+  documentation of custom list fields such as webargs ``DelimitedList``
+  (:pr:`778`).
+- *Backwards-incompatible*: Remove ``OpenAPIVersion`` and use ``packaging.Version``
+  instead (:pr:`801`).
+
 5.2.2 (2022-05-13)
 ******************
 

src/apispec/__init__.py

@@ -3,5 +3,5 @@
 from .core import APISpec
 from .plugin import BasePlugin
 
-__version__ = "5.2.2"
+__version__ = "6.0.0b1"
 __all__ = ["APISpec", "BasePlugin"]