[ci skip] Update versions

Author: mxcl

README.markdown

@@ -8,7 +8,7 @@ This project supports Swift 3.0, 3.1, 3.2 and 4.0; iOS 9, 10 and 11; tvOS 10 and
 ## CocoaPods
 
 ```ruby
-pod "PromiseKit/UIKit", "~> 4.0"
+pod "PromiseKit/UIKit", "~> 6.0"
 ```
 
 The extensions are built into `PromiseKit.framework` thus `import PromiseKit` is
@@ -17,7 +17,7 @@ all that is needed.
 ## Carthage
 
 ```ruby
-github "PromiseKit/UIKit" ~> 1.0
+github "PromiseKit/UIKit" ~> 3.0
 ```
 
 The extensions are built into their own framework: