DEPS = case lists:keyfind(deps, 1, CONFIG) of
           {_, Deps} -> Deps;
           _ -> []
       end,

GUN = {gun, "1.3.0"},

CONFIG1 = case os:getenv("WITH_WS") of
              "true" ->
                  [{deps, [GUN]} | CONFIG];
              _ ->
                  CONFIG
          end,

CONFIG1.