Remove BufferedSink

Author: clue

composer.json

@@ -8,12 +8,10 @@
         "evenement/evenement": "^2.0|^1.0"
     },
     "require-dev": {
-        "react/event-loop": "^0.4|^0.3",
-        "react/promise": "^2.0|^1.0"
+        "react/event-loop": "^0.4|^0.3"
     },
     "suggest": {
-        "react/event-loop": "^0.4",
-        "react/promise": "^2.0"
+        "react/event-loop": "^0.4"
     },
     "autoload": {
         "psr-4": {