Javascript-SDK - 2.0.0

April 11th, 2018

This major release of the Optimizely SDK introduces APIs for Feature Management. It also introduces some breaking changes listed below.

### New Features
* Introduces the `isFeatureEnabled` API to determine whether to show a feature to a user or not.
var enabled = optimizelyClient.isFeatureEnabled('my_feature_key', 'user_1', userAttributes);

* You can also get all the enabled features for the user by calling the following method which returns a list of strings representing the feature keys:
var enabledFeatures = optimizelyClient.getEnabledFeatures('user_1', userAttributes);

* Introduces Feature Variables to configure or parameterize your feature. There are four variable types: `Integer`, `String`, `Double`, `Boolean`.
var stringVariable = optimizelyClient.getFeatureVariableString('my_feature_key', 'string_variable_key', 'user_1');
var integerVariable = optimizelyClient.getFeatureVariableInteger('my_feature_key', 'integer_variable_key', 'user_1');
var doubleVariable = optimizelyClient.getFeatureVariableDouble('my_feature_key', 'double_variable_key', 'user_1');
var booleanVariable = optimizelyClient.getFeatureVariableBoolean('my_feature_key', 'boolean_variable_key', 'user_1');

### Breaking changes
* The `track` API with revenue value as a stand-alone parameter has been removed. The revenue value should be passed in as an entry of the event tags map. The key for the revenue tag is `revenue` and will be treated by Optimizely as the key for analyzing revenue data in results.
var eventTags = {
'revenue': 1200

optimizelyClient.track('event_key', 'user_id', userAttributes, eventTags);
* The package name has changed from `optimizely-client-sdk` to `optimizely-sdk` as we have consolidated both Node and JavaScript SDKs into one.