prepare for release 3.9.0 (#435)

Author: jaeopt

.travis.yml

@@ -108,7 +108,7 @@ jobs:
       os: osx
       osx_image: xcode12.4
       env:
-        - VERSION=3.8.1
+        - VERSION=3.9.0
       install:
         # install hub
         - wget https://github.com/github/hub/releases/download/v2.11.2/hub-darwin-amd64-2.11.2.tgz -O /tmp/hub-darwin-amd64-2.11.2.tgz && tar -xvf /tmp/hub-darwin-amd64-2.11.2.tgz -C /usr/local/opt && ln -s /usr/local/opt/hub-darwin-amd64-2.11.2/bin/hub /usr/local/bin/hub
@@ -125,7 +125,7 @@ jobs:
       os: osx
       osx_image: xcode12.4
       env:
-        - VERSION=3.8.1
+        - VERSION=3.9.0
       install:
         # install hub
         - wget https://github.com/github/hub/releases/download/v2.11.2/hub-darwin-amd64-2.11.2.tgz -O /tmp/hub-darwin-amd64-2.11.2.tgz && tar -xvf /tmp/hub-darwin-amd64-2.11.2.tgz -C /usr/local/opt && ln -s /usr/local/opt/hub-darwin-amd64-2.11.2/bin/hub /usr/local/bin/hub

CHANGELOG.md

@@ -1,5 +1,19 @@
 # Optimizely Swift SDK Changelog
 
+## 3.9.0
+September 15, 2021
+
+### New Features
+* Add new public properties to OptimizelyConfig. ([#417](https://github.com/optimizely/swift-sdk/pull/417), [#418](https://github.com/optimizely/swift-sdk/pull/418))
+	- sdkKey
+ 	- environmentKey
+	- attributes
+	- audiences
+	- events
+	- experimentRules and deliveryRules to OptimizelyFeature
+	- audiences to OptimizelyExperiment
+* For details, refer to our documentation page: [https://docs.developers.optimizely.com/full-stack/v4.0/docs/optimizelyconfig-swift](https://docs.developers.optimizely.com/full-stack/v4.0/docs/optimizelyconfig-swift).
+
 ## 3.8.1
 August 6, 2021
 

README.md

@@ -38,15 +38,15 @@ Add the dependency on the Optimizely Swift SDK with Swift Package Manager in `Xc
 #### CocoaPods 
 1. Add the following lines to the _Podfile_:<pre>
 ```use_frameworks!```
-```pod 'OptimizelySwiftSDK', '~> 3.8.1'```
+```pod 'OptimizelySwiftSDK', '~> 3.9.0'```
 </pre>
 
 2. Run the following command: <pre>``` pod install ```</pre>
 
 Further installation instructions for Cocoapods: https://guides.cocoapods.org/using/getting-started.html
 
 #### Carthage
-1. Add the following lines to the _Cartfile_:<pre>```github "optimizely/swift-sdk" ~> 3.8.1```</pre>
+1. Add the following lines to the _Cartfile_:<pre>```github "optimizely/swift-sdk" ~> 3.9.0```</pre>
 
 2. Run the following command:<pre>```carthage update```</pre>