Add github workflow

.github/workflows/ci.yml

@@ -0,0 +1,84 @@
+name: CI
+
+on: [push, pull_request]
+
+jobs:
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        rust:
+          - stable
+          - beta
+          - nightly
+          - 1.65.0
+
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v2
+
+      - name: Install rust (${{ matrix.rust }})
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ matrix.rust }}
+          profile: minimal
+          override: true
+
+      - name: Cache
+        uses: Swatinem/rust-cache@v1
+
+      - name: Build
+        uses: actions-rs/cargo@v1
+        with:
+          command: build
+          args: --verbose
+
+      - name: Test
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --verbose
+
+  doc:
+    name: Build documentation
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v2
+
+      - name: Install rust
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: nightly
+          profile: minimal
+          override: true
+
+      - name: Build
+        env:
+          RUSTDOCFLAGS: -D warnings
+        run: cargo doc --no-deps --workspace --verbose
+
+  fmt:
+    name: Check formatting
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v2
+
+      - name: Install rust
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          components: rustfmt
+          profile: minimal
+          override: true
+
+      - name: cargo fmt -- --check
+        uses: actions-rs/cargo@v1
+        with:
+          command: fmt
+          args: -- --check