Use GitHub Actions for CI

.github/workflows/ci.yml

@@ -0,0 +1,63 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron: "0 9 7 * *" # Run on at 9am on the 7th of every month
+
+env:
+  RUSTFLAGS: -Dwarnings
+
+jobs:
+  build_and_test:
+    name: Build and test
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macOS-latest]
+        rust: [stable, nightly]
+    steps:
+      - uses: actions/checkout@master
+
+      - name: Install ${{ matrix.rust }}
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ matrix.rust }}
+          override: true
+
+      - name: check
+        uses: actions-rs/cargo@v1
+        with:
+          command: check
+          args: --all --bins --examples
+
+      - name: tests
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --all
+
+  check_fmt_and_docs:
+    name: Checking fmt, clippy, and docs
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          override: true
+
+      - name: setup
+        run: |
+          rustup component add clippy rustfmt
+          rustc --version
+      - name: clippy
+        run: cargo clippy --tests --examples -- -D warnings
+
+      - name: fmt
+        run: cargo fmt --all -- --check
+
+      - name: Docs
+        run: cargo doc --no-deps