ci: configure github actions

.github/workflows/rust.yml

@@ -0,0 +1,52 @@
+name: CI
+
+on: [push, pull_request]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+          - stable
+          - beta
+          - nightly
+          - 1.50.0 # MSRV
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: ${{ matrix.rust }}
+          override: true
+          components: rustfmt, clippy
+
+      - name: Build
+        uses: actions-rs/cargo@v1
+        with:
+          command: build
+
+      - name: Check format
+        uses: actions-rs/cargo@v1
+        with:
+          command: fmt
+          args: --all -- --check
+
+      - name: Check clippy
+        uses: actions-rs/cargo@v1
+        with:
+          command: clippy
+          args: -- -D warnings
+
+      - uses: isbang/compose-action@v0.1
+
+      - name: Run tests
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: -- --test-threads=1