typo
add support for asynchronous response in hackney

Ex:

Url = <<"https://friendpaste.com/_all_languages">>,
Opts = [async],

LoopFun = fun(Ref) ->
    receive
        {Ref, {status, StatusInt, Reason}} ->
            io:format("got status: ~p with reason ~p~n", [StatusInt,
                                                          Reason]),
            loop(StreamRef);
        {Ref, {headers, Headers}} ->
            io:format("got headers: ~p~n", [Headers]),
            loop(StreamRef);
        {Ref, done} ->
            ok;
        {Ref, Bin} ->
            io:format("got chunk: ~p~n", [Bin]),
            loop(StreamRef);

        Else ->
            io:format("else ~p~n", [Else]),
            ok
    end.