Merge pull request #1212 from a-treschilov/feature/doctrine-collections-3x

Add support for doctrine/collections 3.x

Author: veewee

composer.json

@@ -19,7 +19,7 @@
         "composer-plugin-api": "^2.0",
         "amphp/amp": "^3.0",
         "amphp/parallel": "^2.1",
-        "doctrine/collections": "^1.6.8 || ^2.0",
+        "doctrine/collections": "^1.6.8 || ^2.0 || ^3.0",
         "gitonomy/gitlib": "^1.6",
         "laravel/serializable-closure": "^2.0",
         "monolog/monolog": "^2.0 || ^3.0",