message: From now Travis will run on all PHP versions.
diff: @@ -15,7 +15,8 @@ prepare(){
  #------------Only run once-------------
  if [ "${TRAVIS_BUILD_DIR}" ]; then
  - if [ "`php -v | grep "PHP 7\\.2"`" ]; then
  + php_version=`php -r "echo PHP_VERSION_ID;"`
  + if [ ${php_version} -lt 70400 ]; then
  echo "travis ci with docker...\n"
  set -e
  DOCKER_COMPOSE_VERSION="1.21.0"
  