Starting api change to introduce a `Client` class.
Remove blank line in .travis.yml
Remove search() & scan() from Query.
Add phpdoc to Client.
Response: iterate bulk operation results.
Query: Remove server, index and type members.

Finishing clean up started with creation of the Client class.

Also added a magic static factory for new object creation shortcuts.
Client: Add _bulk and HTTP auth support.
Fix tests to work with Query::newInstance().
Client::__toString()
Merge branch 'feature/client'