update flake8-docstrings to minimum version of 1.5.0 to address compatibility issues with pydocstyle 4.x (#203)

Author: mattsb42-aws

tox.ini

@@ -116,8 +116,7 @@ commands = {[testenv:test-upstream-requirements-base]commands}
 basepython = python3
 deps =
     flake8
-    flake8-docstrings
-    pydocstyle<4.0.0
+    flake8-docstrings>=1.5.0
     # https://github.com/JBKahn/flake8-print/pull/30
     flake8-print>=3.1.0
     flake8-bugbear