Fix for Swift 4

Lib/KeychainAccess/Keychain.swift

@@ -1639,7 +1639,7 @@ extension CFError {
     var error: NSError {
         let domain = CFErrorGetDomain(self) as String
         let code = CFErrorGetCode(self)
-        let userInfo = CFErrorCopyUserInfo(self) as! [NSObject: Any]
+        let userInfo = CFErrorCopyUserInfo(self) as! [String: Any]
 
         return NSError(domain: domain, code: code, userInfo: userInfo)
     }