chore: Prepare 1.0.0-beta3 relesae. (#146)

Author: Michael Ng

CHANGELOG.MD

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ## [Unreleased]
 Changes that have landed but are not yet released.	Changes that have landed but are not yet released.
 
+## [1.0.0-beta3] - October 15th, 2019
+
 ### Breaking Changes
 - Refactored EventProcessor and ConfigManager components to no longer require an ExecutionContext be passed in during construction. It will be injected into them by the client factory. [#130](https://github.com/optimizely/go-sdk/pull/130)
 - Moved the entire `optimizely` package from `github.com/optimizely/go-sdk/optimizely` to `github.com/optimizely/go-sdk/pkg` to better follow convention and best practices. [#135](https://github.com/optimizely/go-sdk/pull/135)

pkg/version.go

@@ -18,7 +18,7 @@
 package pkg
 
 // Version is the current version of the client
-const Version = "1.0.0-beta2"
+const Version = "1.0.0-beta3"
 
 // ClientName is the name of the client
 const ClientName = "go-sdk"