.travis.yml

language: php

php:
    - 7.1
    - 7.2
    - 7.3

env:
    matrix:
        - COMPOSER_FLAGS="--prefer-lowest"
        - COMPOSER_FLAGS=""

before_script:
    - travis_retry composer self-update
    - travis_retry composer update ${COMPOSER_FLAGS} --no-interaction --prefer-source

script:
    - composer test