fix(scripts): pydocstyle and cz

For `pydocstyle`, use `--match-dir` switch to prevent traversal into
`venv/` folder.

For `commitizen`, use `cz` instead of `commitizen` as `cz` is present on
all OS's, but `commitizen` is not present in `venv/Scripts` on Windows.

Author: adam-grant-hendry

scripts/test

@@ -22,5 +22,5 @@ ${PREFIX}black commitizen tests --check
 ${PREFIX}isort --check-only commitizen tests
 ${PREFIX}flake8 commitizen/ tests/
 ${PREFIX}mypy commitizen/ tests/
-${PREFIX}pydocstyle --convention=google --add-ignore=D1,D415
-${PREFIX}commitizen check --rev-range origin/master..
+${PREFIX}pydocstyle --convention=google --add-ignore=D1,D415 --match-dir='^(?![.]|venv).*'
+${PREFIX}cz check --rev-range origin/master..