Use glide for dependency management

Fix tests for Go 1.5

Add "Highlight" field to "Hit" structure.

Code formatting

Update index settings API

ElasticSearch 1.7.0 is out, test with that, too

Split Run into two parts.

Return *Response instead of Response so response data is not copied on return

This will make writing request methods which return different response types simpler.

Set content-type to application/json, since that's what is being passed to ElasticSearch

Use interface{} so any JSON-encodable value can be passed in

Call _refresh to ensure index is refreshed before getting the status