Update .travis.yml

.travis.yml

@@ -31,8 +31,10 @@ matrix:
     - php: 7.2
       env: CODECOVERAGE=1 DEFAULT=0
 
-before_script:
+before_install:
   - phpenv config-rm xdebug.ini
+
+before_script:
   - if [[ $PREFER_LOWEST != 1 ]]; then composer install --prefer-source --no-interaction ; fi
   - if [[ $PREFER_LOWEST == 1 ]]; then composer update --prefer-lowest --prefer-stable --prefer-dist --no-interaction ; fi
   - if [[ $PREFER_LOWEST == 1 ]]; then composer require --dev dereuromark/composer-prefer-lowest; fi