Investigate splitting ConsulFactory

[sleberknight]

Note that the ConsulFactory implementation has equals and hashCode even though it doesn't seem like you would ever need to compare two ConsulFactory objects. I do not plan to add these new properties to the existing equals and hashCode methods, and after seeing these methods am considering several future changes:

1. Split ConsulFactory into separate classes, one that contains only configuration, and one for taking that configuration and building the Consul instance.
2. Remove equals and hashCode from the factory class
3. Maybe make the configuration class a "value" or "data" class, where it would (maybe) make more sense to have equals and hashCode
4. Change all the Optional handling across the library, i.e. don't declare fields as Optional and don't pass Optional to methods, etc.

This would be a somewhat large design change, since it would change public APIs. Then again, since we have not released this yet under kiwiproject, we don't need to adhere to the original APIs, at the cost of a little migration pain (in our own services).

Originally posted by @sleberknight in #23 (comment)

[sleberknight]

We now have released this library under kiwiproject, so the original comment is no longer valid regarding changes to public APIs.