please make a new release to hex.pm to support otp24

[dingxinglong]

cowboy version lower than 2.8.0 is using a deprecated_function erlang, get_stacktrace, making all error log to undef error:
Ranch protocol #PID<0.409.0> of listener Plug.Cowboy.TranslatorTest.HTTP (connection #PID<0.408.0>, stream id 1) terminated\n** (exit) :undef

error reproducing:
plug_cowboy: Release v2.5.2
erlang otp: 24
mix test test/plug/cowboy/translator_test.exs

[José Valim]

We support more recent Cowboy versions. You only need to do mix deps.update cowboy. :)