Update .travis.yml

Author: mcordingley

.travis.yml

@@ -7,13 +7,12 @@ php:
 install: composer install
 
 before_script:
-- echo 'xdebug.mode=coverage' >> /etc/php/php.ini
 - curl -L https://codeclimate.com/downloads/test-reporter/test-reporter-latest-linux-amd64 > ./cc-test-reporter
 - chmod +x ./cc-test-reporter
 - ./cc-test-reporter before-build
 
 script:
-- ./vendor/phpunit/phpunit/phpunit --coverage-clover clover.xml
+- XDEBUG_MODE=coverage ./vendor/phpunit/phpunit/phpunit --coverage-clover clover.xml
 
 after_script:
 - ./cc-test-reporter after-build --coverage-input-type clover --id 146c9c0df65c4144142d6065c580dcbed2c0130a2203adae38a4ce13e8afcfca --exit-code $TRAVIS_TEST_RESULT