Support GET /{index}/_mapping and more tests

Complete the support of the _mapping endpoint.
Add more tests for event-style and callback-style.
falso -> false
Merge pull request #72 from draco2003/patch-1

falso -> false
Added index segments API call and test

Change-Id: I41e8880519e681214aa587ddc041d96af703e8fd
Merge pull request #73 from devoncrouse/master

Added index segments API call
Merge pull request #69 from hmalphettes/bulk

Add tests for es#bulk; support index and type
Merge pull request #71 from hmalphettes/mappings

Support GET /{index}/_mapping and more tests