Consumer creation exceptions are not handled

[KannarFr]

When creating to consume a non-exisiting namespace, the java pulsar client prints a lot of exceptions like:

org.apache.pulsar.client.api.PulsarClientException$LookupException:  Policies not found for <tenant>/<namespace> namespace

This is normal, but pulsar4s should provide consumer creation in a Try. WDYT?

[gmethvin]

That probably makes sense, but I'd want to make sure we're consistent about using Try to encapsulate errors anywhere we'd throw. In other words if we make such a change I'd rather break the API all at once rather than changing methods individually to return Try.

That said I'm not really that worried about this case because most people should be using the async APIs anyway.

[KannarFr]

@sksamuel WDYT?

[sksamuel]

I agree with Greg. We should be either all in on Try or just use exceptions.
Really I should have called these methods dosomethingUnsafe and then dosomething() returns a Try. That doesn't help us now though.

[KannarFr]

I agree too. So, let's make breaking changes?

[sksamuel]

I don't think we should break all the methods now was kind of what I was meaning unless it was a 3.0 release, but then we need pulsar to do that too.

I'd be happy to add new methods / deprecate old ones.