[ci] Add a GitHub CI bot

Run coverage also

.github/workflows/linux-ci.yml

@@ -0,0 +1,25 @@
+name: linux-ci
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: install dependencies
+      run: apt-get install meson pkg-config gcc ragel lcov gtk-doc-tools libfreetype6-dev libglib2.0-dev libcairo2-dev libicu-dev libgraphite2-dev # libgirepository1.0-dev
+    - name: run
+      run: meson build -Db_coverage=true -Dglib=true -Dcairo=true -Dicu=true -Dgraphite=true -Dfreetype=true
+    - name: ci
+      run: meson test --print-errorlogs -Cbuild
+    - name: cov
+      run: ninja -Cbuild coverage
+    - uses: codecov/codecov-action@v1
+      with:
+        file: build/meson-logs/coverage.xml