[pre-commit.ci] pre-commit autoupdate (#239)

* [pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/pre-commit/pre-commit-hooks: v2.3.0 → v4.0.1](pre-commit/pre-commit-hooks@v2.3.0...v4.0.1)
- [github.com/psf/black: 19.3b0 → 21.7b0](psf/black@19.3b0...21.7b0)
- [github.com/kynan/nbstripout: master → 0.5.0](kynan/nbstripout@master...0.5.0)

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

.pre-commit-config.yaml

@@ -1,16 +1,16 @@
 repos:
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v2.3.0
+    rev: v4.0.1
     hooks:
       - id: check-yaml
       - id: end-of-file-fixer
       - id: trailing-whitespace
   - repo: https://github.com/psf/black
-    rev: 19.3b0
+    rev: 21.7b0
     hooks:
       - id: black
   - repo: https://github.com/kynan/nbstripout
-    rev: master
+    rev: 0.5.0
     hooks:
       - id: nbstripout
         files: ".ipynb"

CONTRIBUTORS

@@ -12,4 +12,3 @@ Many thanks to the following users who have contributed to improving the content
 @RyPeck
 @zmilicc
 @MridulS
-