Add a GitHub Workflow as CI run (#1238)

CircleCI is limiting how many runs we can do, which results in pipelines
randomly failing when we've used up the credits for this month.

Let's add a github workflow instead. Unfortunately github workflows are
a bit of a toy api, no support for YAML anchors or extending other jobs,
so there's a lot of duplication needed to get a job to do something.

The actions added in this patch help a bit to make the jobs easier to
understand (copied from libwacom).

This only runs on Ubuntu right now.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

.github/workflows/main.yml

@@ -0,0 +1,47 @@
+name: linux
+
+on: [ push, pull_request ]
+
+env:
+  UBUNTU_DEP_BUILD: gcc g++ pkg-config systemd libevdev-dev libglib2.0-dev libjson-glib-dev libsystemd-dev libudev-dev libunistring-dev python3-dev python3-evdev swig
+  UBUNTU_DEP_TEST: check python3-gi python3-lxml valgrind
+  PIP_PACKAGES: meson ninja libevdev pyudev pytest
+
+jobs:
+  build-and-dist:
+    runs-on: ubuntu-20.04
+    strategy:
+      matrix:
+        meson_args:
+          - ''
+          - '-Dbuildtype=plain'
+          - '-Dbuildtype=release'
+          - '-Ddocumentation=true'
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ./.github/actions/pkginstall
+        with:
+          apt: $UBUNTU_DEP_BUILD $UBUNTU_DEP_TEST
+          pip: $PIP_PACKAGES
+      - name: meson test ${{matrix.meson_options}}
+        uses: ./.github/actions/meson
+        with:
+          meson_args: --prefix=$PWD/_instdir ${{matrix.meson_options}}
+          ninja_args: install
+      - name: check installation of data files
+        run:  diff -u <(cd data/devices; ls *.device) <(cd _instdir/share/libratbag; ls *.device)
+      - name: ninja uninstall
+        uses: ./.github/actions/meson
+        with:
+          meson_args: --prefix=$PWD/_instdir
+          ninja_args: uninstall
+      - name: check if any files are left after uninstall
+        run: (test -d _instdir && tree _instdir && exit 1) || exit 0
+      # Capture all the meson logs, even if we failed
+      - uses: actions/upload-artifact@v2
+        if: ${{ always() }}  # even if we fail
+        with:
+          name: meson test logs
+          path: |
+            builddir/meson-logs/testlog*.txt
+            builddir/meson-logs/meson-log.txt