Go-SDK - 1.4.0

- Add MatchRegistry for custom match implementations. ([#286](https://github.com/optimizely/go-sdk/pull/286)) … - Added and refactored audience evaluation logs. ([#280](https://github.com/optimizely/go-sdk/pull/280)) - Add datafile accessor to access config as JSON string. ([#290](https://github.com/optimizely/go-sdk/pull/290)) - Support version audience evaluation following semantic versioning implementation. ([#289](https://github.com/optimizely/go-sdk/pull/289)) - Support number 'less than or equal to' and 'greater than or equal to'. ([#289](https://github.com/optimizely/go-sdk/pull/289))

- Fixed a spelling mistake in go.mod file. ([#285](https://github.com/optimizely/go-sdk/pull/285))

https://github.com/optimizely/go-sdk/releases/tag/v1.4.0