Remove false comment about default hackney config (#405)
Remove false comment about default hackney config (#405)

For the user of the library, there is no default hackney config:

iex(1)> Application.ensure_all_started(:wallaby)
{:ok,
 [:unicode_util_compat, :idna, :mimerl, :certifi, :ssl_verify_fun, :metrics,
  :hackney, :httpoison, :poolboy, :poison, :wallaby]}
iex(2)> Application.get_env(:wallaby, :hackney_options, [])
[]
aaronrenner/wallaby,aaronrenner/wallaby,keathley/wallaby,keathley/wallaby