Java-SDK - 2.0.0-beta

## 2.0.0 Beta
September 29, 2017

This release is a beta release supporting feature flags and rollouts.

### New Features
#### Feature Flag Accessors
You can now use feature flags in the Java SDK. You can experiment on features and rollout features through the Optimizely UI.

- `isFeatureEnabled`
- `getFeatureVariableBoolean`
- `getFeatureVariableDouble`
- `getFeatureVariableInteger`
- `getFeatureVariableString`

### Breaking Changes

- Remove Live Variables accessors
- `getVariableString`
- `getVariableBoolean`
- `getVariableInteger`
- `getVariableDouble`
- Remove track with revenue as a parameter. Pass the revenue value as an event tag instead
- `track(String, String, long)`
- `track(String, String, Map, long)`
- We will no longer run all unit tests in travis-ci against Java 7.
We will still continue to set `sourceCompatibility` and `targetCompatibility` to 1.6 so that we build for Java 6.