add pre-commit

.pre-commit-config.yaml

+-   repo: local
+    hooks:
+    -   id: yapf
+        name: yapf
+        entry: yapf
+        language: system
+        args: [-i, --style .style.yapf]
+        files: \.py$
+
+-   repo: https://github.com/pre-commit/pre-commit-hooks
+    sha: a11d9314b22d8f8c7556443875b731ef05965464
+    hooks:
+    -   id: check-merge-conflict
+    -   id: check-symlinks
+    -   id: end-of-file-fixer
+    -   id: trailing-whitespace
+    -   id: detect-private-key
+    -   id: check-symlinks
+    -   id: check-added-large-files
+-   repo: local
+    hooks:
+    -   id: copyright_checker
+        name: copyright_checker
+        entry: python ./.copyright.hook
+        language: system
+        files: \.(c|cc|cxx|cpp|cu|h|hpp|hxx|proto|py)$
+        exclude: (?!.*third_party)^.*$

.style.yapf

+[style]
+based_on_style = pep8
+column_limit = 80

commit-prepare.sh

+path=$(cd `dirname $0`; pwd)
+cd $path
+
+pip install pre-commit
+pip install yapf
+pre-commit install