CSharp-SDK - 2.2.0

### New Features
* refactor(interface): Adds IOptimizely interface ([#93](https://github.com/optimizely/csharp-sdk/pull/93))
* feat(api): Accepting all types for attributes values ([#102](https://github.com/optimizely/csharp-sdk/pull/102))

### Bug fixes
* fix(whitelistng): Removed logic from bucketing since it is checked in Decision Service. ([#98](https://github.com/optimizely/csharp-sdk/pull/98))
* fix(track): Send decisions for all experiments using an event when using track. ([#100](https://github.com/optimizely/csharp-sdk/pull/100))
* fix(datafile-parsing): Prevent newer versions datafile ([#101](https://github.com/optimizely/csharp-sdk/pull/101))
* fix(api): Only track attributes with valid attribute types. ([#103](https://github.com/optimizely/csharp-sdk/pull/103))

https://github.com/optimizely/csharp-sdk/releases/tag/v2.2.0