Tag 1.0.2rc2

Tag 1.0.2rc1

Tag 1.0.1

Tag v1.0.0

Tag v1.0.0-rc1

Tag 0.3.3

Tag v0.3.2

Tag 0.3.1

Update stats structs to support ES 2.0; Add Thread Pool stats

* Addresses prometheus-community#8
* Update README to note changes in ES 2.0
* Add stats for thread pool

Increment version to 0.2.1