.travis.yml: Revert to using autoblack (TheAlgorithms#2033)

* .travis.yml: Revert to using autoblack

Our autoblack GitHub Action will get us to black compliance without forcing each contributor to learn about, install, and use psf/black on every pull request.

* updating DIRECTORY.md

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>

.travis.yml

@@ -6,7 +6,7 @@ cache: pip
 before_install: pip install --upgrade pip setuptools six
 install: pip install black flake8
 before_script:
-  - black --check .
+  - black --check . || true
   - flake8 --ignore=E203,W503 --max-complexity=25 --max-line-length=120 --statistics --count .
   - scripts/validate_filenames.py  # no uppercase, no spaces, in a directory
   - pip install -r requirements.txt  # fast fail on black, flake8, validate_filenames

DIRECTORY.md

@@ -575,6 +575,7 @@
   * [Ternary Search](https://github.com/TheAlgorithms/Python/blob/master/searches/ternary_search.py)
 
 ## Sorts
+  * [Bead Sort](https://github.com/TheAlgorithms/Python/blob/master/sorts/bead_sort.py)
   * [Bitonic Sort](https://github.com/TheAlgorithms/Python/blob/master/sorts/bitonic_sort.py)
   * [Bogo Sort](https://github.com/TheAlgorithms/Python/blob/master/sorts/bogo_sort.py)
   * [Bubble Sort](https://github.com/TheAlgorithms/Python/blob/master/sorts/bubble_sort.py)