Forgot to move migration test when rebasing

diff --git a/test/migrations/20200806175913_rename_instance_chat_test.exs b/test/pleroma/repo/migrations/rename_instance_chat_test.exs
similarity index 100%
rename from test/migrations/20200806175913_rename_instance_chat_test.exs
rename to test/pleroma/repo/migrations/rename_instance_chat_test.exs