Update changelog and declare support for go 1.6

CHANGELOG.md

@@ -5,6 +5,10 @@
 New Features:
  - Add support for custom offset manager retention durations
    ([#602](https://github.com/Shopify/sarama/pull/602)).
+ - Publish low-level mocks to enable testing of third-party producer/consumer
+   implementations ([#570](https://github.com/Shopify/sarama/pull/570)).
+ - Declare support for Golang 1.6
+   ([#611](https://github.com/Shopify/sarama/pull/611)).
 
 Improvements:
  - Simplified broker locking scheme slightly

README.md

@@ -18,7 +18,7 @@ Sarama is an MIT-licensed Go client library for [Apache Kafka](https://kafka.apa
 Sarama provides a "2 releases + 2 months" compatibility guarantee: we support
 the two latest stable releases of Kafka and Go, and we provide a two month
 grace period for older releases. This means we currently officially support
-Go 1.5 and 1.4, and Kafka 0.9.0 and 0.8.2, although older releases are still
+Go 1.6, 1.5 and 1.4, and Kafka 0.9.0 and 0.8.2, although older releases are still
 likely to work.
 
 Sarama follows semantic versioning and provides API stability via the gopkg.in service.