Java-SDK - 3.2.0-alpha

## 3.2.0-alpha
May 23rd, 2019

### New Features:
- Added support for automatic datafile management via `HttpProjectConfigManager`:
- The [`HttpProjectConfigManager`](
is part of the `core-httpclient-impl` package and is an implementation of the abstract
[`PollingProjectConfigManager`]( class.
- Users must first build the `HttpProjectConfigManager` with an SDK key and then and provide that instance to the Optimizely.Builder.
- An initial datafile can be provided to the `HttpProjectConfigManager` to bootstrap before making http requests for the hosted datafile.
- Requests for the datafile are made in a separate thread and are scheduled with fixed delay.
- Configuration updates can be subscribed to via the `Optimizely#addUpdateConfigNotificationHandler` or by subscribing to
the NotificationCenter built with the `HttpProjectConfigManager`.
- Added `AsyncEventHandler.Builder` to be consistent with other Optimizely resources.
- The [`OptimizelyFactory`](
was included in the `core-httpclient-impl` package and provides basic methods for instantiating the Optimizely SDK with a minimal number of parameters.
- Default configuration options for `HttpProjectConfigManager` and `AsyncEventHandler` can be overwritten using Java system properties, environment variables or via an `` file
to avoid hard coding the configuration options.

### Deprecated
- `Optimizely.builder(String, EventHandler)` was deprecated in favor of pure builder methods `withConfigManager` and `withEventHandler`.