Update .travis.yml

.travis.yml

@@ -29,7 +29,6 @@ before_script:
   - composer self-update
   - composer install --prefer-dist --no-interaction
 
-  - composer require yangqi/htmldom:dev-master
   - if [[ $PHPCS != 1 ]]; then composer require phpunit/phpunit:"^5.7|^6.0"; fi
 
   - sh -c "if [ '$DB' = 'mysql' ]; then mysql -e 'CREATE DATABASE cakephp_test;'; fi"