CI: add a simple github action

.github/workflows/CI.yml

@@ -0,0 +1,69 @@
+on:
+  push:
+    branches: [master]
+  pull_request:
+
+name: CI
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    container:
+      image: fedora:latest
+    strategy:
+      matrix:
+        rust:
+          - stable
+          - beta
+          - nightly
+          - "1.40.0"
+    steps:
+      - run: sudo dnf install -y gcc gtk3-devel graphene-devel glib2-devel git xorg-x11-server-Xvfb
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ matrix.rust }}
+          override: true
+      - uses: actions-rs/cargo@v1
+        name: "Docs"
+        with:
+          command: doc
+      - run: xvfb-run --auto-servernum cargo test
+      - uses: actions-rs/cargo@v1
+        name: "Build"
+        with:
+          command: build
+      - run: git diff -R --exit-code
+      - name: Cleanup xvfb pidx
+        uses: bcomnes/cleanup-xvfb@v1
+
+  fmt:
+    name: rust fmt
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          override: true
+      - run: rustup component add rustfmt
+      - uses: actions-rs/cargo@v1
+        with:
+          command: fmt
+          args: --all -- --check
+
+  checker:
+    name: gtk-rs checker
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2
+        with:
+          repository: gtk-rs/checker
+          ref: master
+          path: checker
+      - working-directory: checker
+        run: cargo build --release
+      - run: "./checker/target/release/checker ."
+      - run: "./checker/check_init_asserts"

Cargo.toml

@@ -27,4 +27,4 @@ members = [
   "pangocairo/sys",
 ]
 
-exclude = ["gir"]
+exclude = ["gir", "checker"]