add SubscriptionOptions parameter to newSubscription

[PhilipDukhov]

Allows authenticating for private channels. Fixes #52

[FZambia]

@PhilipDukhov many thanks! That's an unfortunate miss..

Could you please put options before listener in the constructor? To match order of arguments in a Client constructor.

[PhilipDukhov]

@FZambia sure, done 👍

[PhilipDukhov]

Passed the checks

[FZambia]

Since we keep the old API here, then what is it better in your opinion:

1. Match Client constructor and have SubscriptionOptions a second argument in new API?
2. Or, have SubscriptionOptions a third argument in new API (after listener, like in your original PR version)?

For me 2 seems more natural (more IDE friendly as the beginning of two methods match), what do you think?

[PhilipDukhov]

I'd prefer using same style in whole project, so I'd prefer 1.

Also even if we could make breaking changes, I think options on the second place still looks more natural - if you create listener on place, it's easier to read with listener as the last argument, e.g.

client.newSubscription(
        "chat:index",
        new SubscriptionOptions(),
        new SubscriptionEventListener() {
            @Override
            public void onSubscribing(Subscription sub, SubscribingEvent event) {
                MainActivity.this.runOnUiThread(() -> tv.setText(String.format("Subscribing to %s, reason: %s", sub.getChannel(), event.getReason())));
            }
        }
);