Switch CI to Github Actions (#15403)

.github/workflows/tests.yml

@@ -0,0 +1,52 @@
+name: Tests
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+
+  codestyle:
+    runs-on: macos-latest
+    steps:
+    - uses: actions/checkout@v2
+    - run: brew install clang-format
+      name: Install clang-format
+    - run: clang-format --version
+    - run: bash ./tools/format-code.sh
+      name: Run code formatter
+    - run: git diff --quiet HEAD
+      name: Check if the styling guide is followed
+
+  amd64_linux_clang:
+    runs-on: ubuntu-18.04
+    steps:
+    - uses: actions/checkout@v2
+    - run: sudo apt -y -qq update
+    - run: sudo apt install -y clang cmake qt5-default libqt5webkit5-dev python
+      name: Install requirements
+    - run: clang++ --version && cmake --version && qmake --version && python --version
+      name: Display tools version
+    - run: CC=clang CXX=clang++ ./configure
+    - run: make
+    - run: file ./bin/phantomjs
+    - run: ./bin/phantomjs --version
+    - run: make check
+
+  amd64_linux_gcc:
+    runs-on: ubuntu-18.04
+    steps:
+    - uses: actions/checkout@v2
+    - run: sudo apt -y -qq update
+    - run: sudo apt install -y g++ cmake qt5-default libqt5webkit5-dev python
+      name: Install requirements
+    - run: g++ --version && cmake --version && qmake --version && python --version
+      name: Display tools version
+    - run: ./configure
+    - run: make
+    - run: file ./bin/phantomjs
+    - run: ./bin/phantomjs --version
+    - run: make check
+