[pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/psf/black: 21.5b1 → 21.5b2](psf/black@21.5b1...21.5b2)

Author: pre-commit-ci[bot]

.pre-commit-config.yaml

@@ -14,7 +14,7 @@ repos:
           exclude: ^docs/.*|.*.md
 
   -   repo: https://github.com/psf/black
-      rev: 21.5b1
+      rev: 21.5b2
       hooks:
         - id: black
           language_version: python3