Added AllMarketTickers channel

[tonyskulk]

No description provided.

[xezon]

Very nice.

[joaopsilva]

This looks good, thanks @tonyskulk . Could you please add an example of using this to the test directory?

[joaopsilva]

Could you please replace this to use the ToStringBuilder that is used in other transfer objects? Thanks.

[tonyskulk]

Switched to ToStringBuilder and made a very simple self-explaining example

[joaopsilva]

Hi @tonyskulk , could you please have a look at the issue reported in #72? Thanks.

[mjwchapman]

Would be useful to update the example so that it highlights the problematic code path, e.g.

        webSocketClient.onAllMarketTickersEvent(eventList -> {
            try {
                for (AllMarketTickersEvent event : eventList) {
                    System.out.println(event);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        });