Update .travis.yml

Author: cretueusebiu

.travis.yml

@@ -6,11 +6,9 @@ php:
 
 install:
   - travis_retry composer install --no-interaction --prefer-dist --no-suggest
-  - travis_retry yarn install
 
 script:
   - vendor/bin/phpunit
-  - yarn build
 
 notifications:
   email: false