Update README

README.md

@@ -1,9 +1,11 @@
 # KeychainAccess
 [![CI Status](http://img.shields.io/travis/kishikawakatsumi/KeychainAccess.svg)](https://travis-ci.org/kishikawakatsumi/KeychainAccess)
-[![Coverage Status](https://img.shields.io/coveralls/kishikawakatsumi/KeychainAccess.svg)](https://coveralls.io/github/kishikawakatsumi/KeychainAccess?branch=master)
+[![codecov](https://codecov.io/gh/kishikawakatsumi/KeychainAccess/branch/master/graph/badge.svg)](https://codecov.io/gh/kishikawakatsumi/KeychainAccess)
 [![Carthage compatible](https://img.shields.io/badge/Carthage-compatible-4BC51D.svg?style=flat)](https://github.com/Carthage/Carthage)
 [![Version](https://img.shields.io/cocoapods/v/KeychainAccess.svg)](http://cocoadocs.org/docsets/KeychainAccess)
 [![Platform](https://img.shields.io/cocoapods/p/KeychainAccess.svg)](http://cocoadocs.org/docsets/KeychainAccess)
+[![Swift 3.x](https://img.shields.io/badge/Swift-3.x-orange.svg?style=flat)](https://swift.org/)
+[![Swift 4.0](https://img.shields.io/badge/Swift-4.0-orange.svg?style=flat)](https://swift.org/)
 
 KeychainAccess is a simple Swift wrapper for Keychain that works on iOS and OS X. Makes using Keychain APIs extremely easy and much more palatable to use in Swift.
 
@@ -21,7 +23,7 @@ KeychainAccess is a simple Swift wrapper for Keychain that works on iOS and OS X
 - **[Support Shared Web Credentials (iOS 8+)](#shared_web_credentials)**
 - [Works on both iOS & OS X](#requirements)
 - [watchOS and tvOS are supported](#requirements)
-- **[Swift 3 & Swift 2.3 compatible](#requirements)**
+- **[Swift 4 & Swift 3 compatible](#requirements)**
 
 ## :book: Usage
 
@@ -537,7 +539,8 @@ item: [authenticationType: Default, key: honeylemon, server: github.com, class:
 | **v2.2.x** | iOS 8+, OSX 10.9+, watchOS 2+, tvOS 9+ | 2.0, 2.1      |
 | **v2.3.x** | iOS 8+, OSX 10.9+, watchOS 2+, tvOS 9+ | 2.0, 2.1, 2.2 |
 | **v2.4.x** | iOS 8+, OSX 10.9+, watchOS 2+, tvOS 9+ | 2.2, 2.3      |
-| **v3.x**   | iOS 8+, OSX 10.9+, watchOS 2+, tvOS 9+ | 3.0           |
+| **v3.0.x** | iOS 8+, OSX 10.9+, watchOS 2+, tvOS 9+ | 3.x           |
+| **v3.1.x** | iOS 8+, OSX 10.9+, watchOS 2+, tvOS 9+ | 3.x, 4.0      |
 
 ## Installation