github action: check coding style of commits

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>

.github/workflows/coding-style.yml

@@ -0,0 +1,14 @@
+name: code-style
+on: push
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 2
+    - uses: yshui/git-clang-format-lint@v1.7
+      with:
+        base: ${{ github.event.ref }}~1