Cloudant query support

Added code to create a simple index with integration tests using Cloudant query API #53 . Before adding more features, wanted to have a quick review of the components. We don't have querying yet. If okay, will add delete/listing of indices, followed by query.
`protected` and `virtual` a design decision I have taken with this SDK. Want people to be able to extend and override if they want as much as possible.