Revert "Merge branch 'streamer-refactoring' into 'develop'"

This reverts merge request !1653

test/notification_test.exs

@@ -69,7 +69,16 @@ defmodule Pleroma.NotificationTest do
   end
 
   describe "create_notification" do
-    @tag needs_streamer: true
+    setup do
+      GenServer.start(Streamer, %{}, name: Streamer)
+
+      on_exit(fn ->
+        if pid = Process.whereis(Streamer) do
+          Process.exit(pid, :kill)
+        end
+      end)
+    end
+
     test "it creates a notification for user and send to the 'user' and the 'user:notification' stream" do
       user = insert(:user)
       task = Task.async(fn -> assert_receive {:text, _}, 4_000 end)