Travis fix for PHP 7.3 Xdebug coverage configuration

Author: leith

.travis.yml

@@ -9,6 +9,10 @@ php:
   - "7.0"
   - "5.6"
 
+before_install:
+  # Enable Xdebug coverage mode
+  - echo 'xdebug.mode="coverage"' >> ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/travis.ini
+
 before_script:
   - travis_retry composer self-update
   - travis_retry composer install --no-interaction --dev --prefer-source