Update Installation guide to current version (#2395)

README.md

@@ -94,7 +94,7 @@ platform :ios, '10.0'
 use_frameworks!
 
 target '<Your Target Name>' do
-    pod 'Alamofire', '~> 4.5'
+    pod 'Alamofire', '~> 4.6'
 end
 ```
 
@@ -118,7 +118,7 @@ $ brew install carthage
 To integrate Alamofire into your Xcode project using Carthage, specify it in your `Cartfile`:
 
 ```ogdl
-github "Alamofire/Alamofire" ~> 4.5
+github "Alamofire/Alamofire" ~> 4.6
 ```
 
 Run `carthage update` to build the framework and drag the built `Alamofire.framework` into your Xcode project.