Add CI setting

.github/workflows/ci.yml

@@ -0,0 +1,25 @@
+name: CI
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Install Rust stable
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          override: true
+
+      - name: Install rustfmt
+        run: rustup component add rustfmt
+
+      - name: Check code formatting
+        run: cargo fmt -- --check
+
+      - name: Run tests
+        run: cargo test --all