Add :append to stream_mode, closes #10421
Add :append to stream_mode, closes #10421

kelvinst/elixir,kelvinst/elixir,michalmuskala/elixir,kimshrier/elixir,kimshrier/elixir,pedrosnk/elixir,pedrosnk/elixir,ggcampinho/elixir,ggcampinho/elixir,joshprice/elixir,elixir-lang/elixir