Support for regex subscriptions

[gmethvin]

The Java client allows you to subscribe to multiple topics using a pattern like

Pattern allTopicsInNamespace = Pattern.compile("persistent://public/default/.*");
Consumer allTopicsConsumer = consumerBuilder.topicsPattern(allTopicsInNamespace).subscribe();

It should be possible to provide a Scala interface to achieve this using a Regex for the pattern.

[sksamuel]

Quite right, that's quite an omission actually.

[sksamuel]

I've added support for this but cannot get the tests to pass currently. Baffling.

[sksamuel]

Tests sorted. 2.1.2 released with topic patterns support. Slight tweak to the order of params in the consumer.