ci: add github actions

Closes #2

.github/workflows/ci.yml

@@ -0,0 +1,106 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  tests:
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - ubuntu-latest
+          - macos-latest
+          - windows-latest
+        rust:
+          - 1.51.0 # msrv
+          - stable
+          - beta
+          - nightly
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Restore cargo cache
+        uses: actions/cache@v2.1.7
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
+          key: ${{ matrix.os }}-cargo-${{ matrix.rust }}-${{ hashFiles('Cargo.lock') }}
+
+      - name: Toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: ${{ matrix.rust }}
+          override: true
+
+      - name: Run tests
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --all-features --verbose
+  
+  clippy:
+    name: clippy (ubuntu-latest, stable)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          override: true
+          components: clippy
+
+      - name: Restore cargo cache
+        uses: actions/cache@v2.1.7
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
+          key: ${{ runner.os }}-cargo-stable-${{ hashFiles('Cargo.lock') }}
+
+      - name: Check clippy
+        uses: actions-rs/cargo@v1
+        with:
+          command: clippy
+          args: -- -D warnings
+  
+  fmt:
+    name: fmt (ubuntu-latest, stable)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          override: true
+          components: rustfmt
+
+      - name: Restore cargo cache
+        uses: actions/cache@v2.1.7
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
+          key: ${{ runner.os }}-cargo-stable-${{ hashFiles('Cargo.lock') }}
+
+      - name: Check format
+        uses: actions-rs/cargo@v1
+        with:
+          command: fmt
+          args: --all -- --check