strategy:
      matrix:
        php:
          - '7.1'
          - '7.2'
          - '7.3'
          - '7.4'
        composer-dependencies:
          - highest
        include:
          - php: '7.1'
            composer-dependencies: lowest
          - php: '7.4'
            composer-dependencies: lowest
          - php: '7.1'
            symfony-require: '3.4.*'
            composer-dependencies: highest
          - php: '7.1'
            symfony-require: '4.4.*'
            composer-dependencies: highest
          - php: '7.2'
            symfony-require: '5.1.*'
            composer-dependencies: highest
          - php: '7.2'
            symfony-require: '5.2.*'
            composer-dependencies: highest