index_range edge case fix

After a new index is created and your search time range is less than
the index size, the newest index wasn't included.
Merge pull request #211 from nitper/index_edge_case

index_range edge case fix
Fix for default index bug
fixing index_range requested bug. from should not increment, only step time should
Merge pull request #216 from michaelgibson/kibana-ruby

fixing index_range requested bug. from should not increment, only step time should
Merge remote-tracking branch 'upstream/kibana-ruby' into kibana-ruby