Java-SDK - 2.0.0-beta3

# 2.0.0 Beta 3
January 5, 2018

This release is a third beta release supporting feature flags and rollouts. It includes all the same new features and breaking as the last beta release.

## Bug Fixes
SDK checks for null values in the Feature API parameters.
* If isFeatureEnabled is called with a null featureKey or a null userId, it will return false immediately.
* If any of getFeatureVariable are called with a null featureKey, variableKey, or userId, null will be returned immediately.

https://github.com/optimizely/java-sdk/releases/tag/2.0.0-beta3