Swift-SDK - 3.2.0

## 3.2.0
January 15, 2020

This release includes a new API to access project configuration data and other feature enhancements. It also fixes known bugs.

### New Features
* OptimizelyConfig ([#274](https://github.com/optimizely/swift-sdk/pull/274)):
* Call `getOptimizelyConfig()` to get a snapshot of project configuration static data.
* It returns an `OptimizelyConfig` instance which includes a datafile revision number, all experiments, and feature flags mapped by their key values.
* For details, refer to our documentation page: [https://docs.developers.optimizely.com/full-stack/docs/optimizelyconfig-swift](https://docs.developers.optimizely.com/full-stack/docs/optimizelyconfig-swift).
* Add LogEvent Notification ([#263](https://github.com/optimizely/swift-sdk/pull/263)):
* Register an event listner with `addLogEventNotificationListener()`.
* The lister will be called when events are dispatched to the server.
* Turn on "Allow app extensions only" flag in build settings ([#277](https://github.com/optimizely/swift-sdk/pull/277))

### Bug Fixes
- When timerInterval is set to a negative value, EventDispatcher is changed to use the default interval value for batching (instead of disabling batch). Batching is disabled when the timerInterval is set to zero. ([#268](https://github.com/optimizely/swift-sdk/pull/268))

### Breaking Changes
- Upgrade required platforms from iOS9+/tvOS9+ to iOS10+/tvOS10+ ([#284](https://github.com/optimizely/swift-sdk/pull/284))