require branch until swagger 2.1 is tagged

Author: Tobion

composer.json

@@ -16,7 +16,7 @@
         "symfony/finder": "^4.4|^5.0",
         "symfony/framework-bundle": "^4.4|^5.0",
         "symfony/routing": "^4.4|^5.0",
-        "zircote/swagger-php": "^2.0.14"
+        "zircote/swagger-php": "2.x-dev"
     },
     "require-dev": {
         "symfony/phpunit-bridge": "^5.0@dev"