Action description for cmake build and test - out it into .github/workflows

cmake-action.yml

name: CI
on:
  push:
    branches: [ master ]

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v2
    - name: Update apt
      run: sudo apt update
    - name: Install GCC
      run: sudo apt install gcc -y
    - name: Install CMake
      run: sudo apt install cmake -y
    - name: Install boost
      run: sudo apt install libboost-all-dev -y
    - name: Install SDL2
      run: sudo apt install libsdl2-dev libsdl2-ttf-dev libsdl2-image-dev libsdl2-mixer-dev -y --fix-missing
    - name: build
      run: |
        mkdir bin
        cd bin
        cmake ..
        cmake --build .
        ctest -V -R LACUNA_AUTOMATED