Updated coverall travis configuration

Author: paquettg

.travis.yml

@@ -15,6 +15,6 @@ script:
   - php vendor/bin/phpunit --coverage-clover build/logs/clover.xml
 
 after_script:
-  - php vendor/bin/coveralls
+  - travis_retry php vendor/bin/coveralls
   - wget https://scrutinizer-ci.com/ocular.phar
   - php ocular.phar code-coverage:upload --format=php-clover build/logs/clover.xml