Ruby-SDK - 3.2.0

## 3.2.0
July 25th, 2019

### New Features:
* Added support for automatic datafile management via `HTTPProjectConfigManager`:
* The [`HTTPProjectConfigManager`](https://github.com/optimizely/ruby-sdk/blob/master/lib/optimizely/config_manager/http_project_config_manager.rb) is an implementation of the Interface
[`ProjectConfigManager`](https://github.com/optimizely/ruby-sdk/blob/master/lib/optimizely/config_manager/project_config_manager.rb).
- Users must first build the `HTTPProjectConfigManager` with an SDK key and then provide that instance to the `Optimizely` instance.
- 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 NotificationCenter built with the `HTTPProjectConfigManager`.
- `Optimizely` instance must be disposed after the use or `HTTPProjectConfigManager` must be disposed after the use to release resources.
- The [`OptimizelyFactory`](https://github.com/optimizely/ruby-sdk/blob/master/lib/optimizely/optimizely_factory.rb) provides basic methods for instantiating the Optimizely SDK with a minimal number of parameters. Check [`README.md`](https://github.com/optimizely/ruby-sdk#initialization-by-optimizelyfactory) for more details.

https://github.com/optimizely/ruby-sdk/releases/tag/3.2.0