Update Read me file to describe how to use V2.1

Author: JakeLin

README.md

@@ -1,13 +1,20 @@
 Swift Weather
 ============
 
-SwiftWeather is an iOS weather app developed in Swift language. The app can support iPhone 4(s), iPhone 5(s), iPhone 6 and iPhone 6 Plus. The app also support Today Widgets.
+SwiftWeather is an iOS weather app developed in Swift language. The app can support iPhone 4(s), iPhone 5(s), iPhone 6 and iPhone 6 Plus. The app also supports Today Widgets.
 
 ## Notices
-The current version is working with Xcode Version 6.3 (6D570) and Version 6.3.1 (6D1002), I have been updating the app to support the lastest version of Xcode, if you have any issue, please check the Xcode version. If there is still a problem with the supported versions, please raise an issue, thanks. 
+The current version is working with Xcode Version 6.4 (6E35b). If you have any issue, please check the Xcode version. If there is still a problem with the supported versions, please raise an issue, thanks. 
 
-## Version 2
-This is version 2. I have ugraded the entire project to use [Carthage](https://github.com/Carthage/Carthage), [Alamofire](https://github.com/Alamofire/Alamofire) and [SwiftyJSON](https://github.com/SwiftyJSON/SwiftyJSON). And the app can only support iOS8+, if you want to support iOS7 or use CocoaPods and AFNetworking. Please have a look at [README.v1.md](https://github.com/JakeLin/SwiftWeather/blob/master/README.v1.md) and Release [Using Cocoapods and AFNetworking](https://github.com/JakeLin/SwiftWeather/releases/tag/V1). Happy coding.
+## Version 2.1
+This is version 2.1. I have remove Carthage because some developers don't have a paid Apple iOS developer account and they have issues to build Carthage packages. 
+
+There are two major version for the app released before.
+
+* V1.0 - Support iOS 7+ using CocoaPods and AFNetworking. [README.v1.md](https://github.com/JakeLin/SwiftWeather/blob/master/README.v1.md) and [Release V1 - Using Cocoapods and AFNetworking](https://github.com/JakeLin/SwiftWeather/releases/tag/V1)
+* V2.0 - Support iOS 8+ using Carthage, Alamofire and SwiftyJSON. [README.v2.md](https://github.com/JakeLin/SwiftWeather/blob/master/README.v2.md) and [Release V2.0](https://github.com/JakeLin/SwiftWeather/releases/tag/v2.0)
+
+V2.1 will be the last version support iOS 8. I am working on Xcode 7 to support iOS 9 only features like `UIStackView`. Happy coding.
 
 ## Screenshots
 ![Loading](https://raw.githubusercontent.com/JakeLin/SwiftWeather/master/screenshots/loading-33.png)
@@ -19,26 +26,39 @@ This is version 2. I have ugraded the entire project to use [Carthage](https://g
 
 ## Used features
 * Swift Programming Language
-* [Carthage](https://github.com/Carthage/Carthage)
 * [Alamofire](https://github.com/Alamofire/Alamofire)
 * [SwiftyJSON](https://github.com/SwiftyJSON/SwiftyJSON)
 * Core Location
 * Using Framework to share code between targets(app and widget).
 
 
-## Known issues
-Because we are using [Carthage](https://github.com/Carthage/Carthage) to build the third party packages. There are some build warings like `ld: warning: linking against dylib not safe for use in application extensions: /Build/Products/Debug-iphoneos/Alamofire.framework/Alamofire`
-
 ## How to build
-Because the app uses carthage, we need to install carthage. To install the carthage tool on your system, please download and run the Carthage.pkg file for the latest [release](https://github.com/Carthage/Carthage/releases), then follow the on-screen instructions..
-
-1. Open Terminal app.
-2. Change directory to the project folder. `cd $project_dir`
-3. Use `ls` to list all the file to check whether *Cartfile* file is in the folder? 
-4. If the *Cartfile* has been found, then execute `carthage update`.This will fetch dependencies into a Carthage/Checkouts folder, then build each one.
-5. On your application targets’ “General” settings tab, in the “Linked Frameworks and Libraries” section, drag and drop each framework you want to use from the Carthage/Build folder on disk. In our project, which are `Alamofire` and `SwiftyJSON`
-7. Press *Cmd + B* to build the app.
-8. Press *Cmd + R* to run the app on Simulator.
+
+1) Download the repository
+
+```
+$ git clone https://github.com/JakeLin/SwiftWeather.git
+$ cd SwiftWeather
+```
+
+2) Initialize submodule dependancies
+
+```
+$ git submodule update --init --recursive
+```
+
+3) Open the project in Xcode
+
+```
+$ open "Swift Weather.xcodeproj"
+```
+
+4) Compile and run the app in your simulator
+
+# Requirements
+
+- Xcode 6.4
+- iOS 8
 
 ## Credits
 * Thanks to [johnsonjake](https://github.com/johnsonjake) for adding iOS 8 support and improving the UI/UX.