Use latest php-coveralls

Author: chadicus

.travis.yml

@@ -15,4 +15,4 @@ before_script:
   - composer update $PREFER_LOWEST
 script:
   - ./vendor/bin/phpunit --coverage-clover clover.xml
-after_success: ./vendor/bin/coveralls -v
+after_success: ./vendor/bin/php-coveralls -v

composer.json

@@ -34,7 +34,7 @@
         "sort-packages": true
     },
     "require-dev": {
-        "php-coveralls/php-coveralls": "^1.0",
+        "php-coveralls/php-coveralls": "^2.1",
         "phpunit/phpunit": "^6.5.2",
         "squizlabs/php_codesniffer": "^3.2"
     },