Update travis build

Author: Riimu

.travis.yml

@@ -1,5 +1,6 @@
 language: php
 sudo: false
+dist: trusty
 
 php:
   - 5.6
@@ -15,7 +16,7 @@ before_install:
   - composer self-update
 
 install:
-  - composer require --no-update --no-interaction "phpunit/phpunit:*" "squizlabs/php_codesniffer:*" "fabpot/php-cs-fixer:*"
+  - composer require --no-update --no-interaction "phpunit/phpunit:*" "squizlabs/php_codesniffer:*" "friendsofphp/php-cs-fixer:*"
   - travis_retry composer update --no-interaction --prefer-source
   - travis_retry wget https://scrutinizer-ci.com/ocular.phar