Update fabpot/php-cs-fixer requirement to ~1|~0

Updates the requirements on [fabpot/php-cs-fixer](https://github.com/FriendsOfPHP/PHP-CS-Fixer) to permit the latest version.
- [Release notes](https://github.com/FriendsOfPHP/PHP-CS-Fixer/releases)
- [Changelog](https://github.com/FriendsOfPHP/PHP-CS-Fixer/blob/2.12/CHANGELOG.md)
- [Commits](https://github.com/FriendsOfPHP/PHP-CS-Fixer/commits/v2.12.2)

Signed-off-by: dependabot[bot] <support@dependabot.com>

composer.json

@@ -11,7 +11,7 @@
   "require-dev": {
     "phpunit/phpunit": "~4",
     "mockery/mockery": ">=0.9.3",
-    "fabpot/php-cs-fixer": "~1",
+    "fabpot/php-cs-fixer": "~1|~0",
     "squizlabs/php_codesniffer": "~2|~0",
     "codeclimate/php-test-reporter": "dev-master"
   },