Updated readme for version bump

README.md

@@ -83,7 +83,7 @@ $ brew install carthage
 To integrate SnapKit into your Xcode project using Carthage, specify it in your `Cartfile`:
 
 ```ogdl
-github "SnapKit/SnapKit" ~> 3.0.2
+github "SnapKit/SnapKit" ~> 3.1.2
 ```
 
 Run `carthage update` to build the framework and drag the built `SnapKit.framework` into your Xcode project.