pre-commit: autoupdate hook versions (#123)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]

.pre-commit-config.yaml

@@ -14,11 +14,11 @@ repos:
       - id: isort
   # https://github.com/python/black#version-control-integration
   - repo: https://github.com/python/black
-    rev: 21.6b0
+    rev: 21.7b0
     hooks:
       - id: black
   - repo: https://github.com/keewis/blackdoc
-    rev: v0.3.3
+    rev: v0.3.4
     hooks:
       - id: blackdoc
   - repo: https://gitlab.com/pycqa/flake8