Facebook認証後（ログイン後）別SBのビューを遷移したいです。

swift4
xcode9.2
Firebase

LogInViewControllerにあるFBログインボタンをタップして、
ポップアップの（Continue）を選択し、
（次へ）で進んだ後に、
異なるビューへ（NavigationController → RAMAnimatedTabBarController）
コードで遷移したいのですが上手く行きません。

不足箇所をご指摘して頂きたいです。
よろしくお願いします。

（AppDelegateです）
import UIKit
import Firebase
import FirebaseAuth
import GoogleSignIn
import FBSDKCoreKit
import RAMAnimatedTabBarController

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate, GIDSignInDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

        print("アプリ起動時の処理だよ")
        FirebaseApp.configure()


        FBSDKApplicationDelegate.sharedInstance().application(application, didFinishLaunchingWithOptions: launchOptions)

        GIDSignIn.sharedInstance().clientID = FirebaseApp.app()?.options.clientID
        GIDSignIn.sharedInstance().delegate = self
        return true
    }





    func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey : Any] = [:]) -> Bool {
        var handled:Bool = false

        if url.scheme == "fb1014972461988152" {
            handled = FBSDKApplicationDelegate.sharedInstance().application(app, open: url, options: options)



        } else if url.scheme == "179603253813-oahjjd5qqh47ca5c7nvsoripcbn7kcvm" {
            handled = GIDSignIn.sharedInstance().handle(url, sourceApplication:options[UIApplicationOpenURLOptionsKey.sourceApplication] as? String!, annotation: options[UIApplicationOpenURLOptionsKey.annotation])
        }
        return handled
    }





        func sign(_ signIn: GIDSignIn!, didSignInFor user: GIDGoogleUser!, withError error: Error?)
        {
            if let error = error {
                print(error.localizedDescription)
                return
            }
            print("Googleログインが成功したよ")

            guard let authentication = user.authentication else { return }

            let credential = GoogleAuthProvider.credential(withIDToken: authentication.idToken,
                                                           accessToken: authentication.accessToken)


            Auth.auth().signIn(with: credential, completion: { (user, error) in
                if let error = error{
                    print(error.localizedDescription)
                    return
                }
                print("Firebaseに正常にログインしたよ")
            })}

    func sign(_  signIn: GIDSignIn!, didDisconnectWith user: GIDGoogleUser!, withError error: Error!) {

        }



    func applicationWillResignActive(_ application: UIApplication) {
        print("アプリ閉じそう")
    }
    func applicationDidEnterBackground(_ application: UIApplication) {
        print("アプリ閉じた")
    }
    func applicationWillEnterForeground(_ application: UIApplication) {
        print("アプリ開きそう")
    }
    func applicationDidBecomeActive(_ application: UIApplication) {
        print("アプリ開いた")
        FBSDKAppEvents.activateApp() //Facebookでも独自のカスタムイベントを定義して記録することができるようです。これいらないか
    }
    func applicationWillTerminate(_ application: UIApplication) {
        print("フリックしてアプリ終了")
    }


}

（LogInViewControllerです）

import UIKit
import Firebase
import FirebaseAuth
import GoogleSignIn
import FBSDKCoreKit
import FBSDKLoginKit
import RAMAnimatedTabBarController

class LogInViewController: UIViewController, GIDSignInUIDelegate {

    @IBOutlet weak var GIDSignInButton: GIDSignInButton!

    @IBOutlet weak var FBSDKLoginButton:FBSDKLoginButton!

    override func viewDidLoad() {

    self.navigationItem.hidesBackButton = true
    super.viewDidLoad()
    GIDSignIn.sharedInstance().uiDelegate = self
    GIDSignIn.sharedInstance().signIn()
}



    func loginButton(loginButton: FBSDKLoginButton!, didCompleteWithResult result: FBSDKLoginManagerLoginResult!, error: NSError!) {

        if let error = error {
            print(error.localizedDescription)
            return
        }
        // ...

    let credential = FacebookAuthProvider.credential(withAccessToken:
        FBSDKAccessToken.current().tokenString)



        Auth.auth().signIn(with: credential) { (user, error) in

            print("User Signed Into Firebase")
        }

        let storyboard: UIStoryboard = UIStoryboard(name: "RAMAnimatedTabBar", bundle: nil)
        let nextView = storyboard.instantiateInitialViewController()
        self.present(nextView!, animated: true, completion: nil)




    }


func sign(_ signIn: GIDSignIn!, didSignInFor user: GIDGoogleUser!,withError error: Error?) {

    if let error = error {
        print(error.localizedDescription)
        return
    }
    print("User signed into google")

    let authentication = user.authentication
    let credential = GoogleAuthProvider.credential(withIDToken: (authentication?.idToken)!,
                                                      accessToken: (authentication?.accessToken)!)


    Auth.auth().signIn(with: credential) { (user, error) in

       print("User Signed Into Firebase")
    }

    let storyboard: UIStoryboard = UIStoryboard(name: "RAMAnimatedTabBar", bundle: nil)
    let nextView = storyboard.instantiateInitialViewController()
    self.present(nextView!, animated: true, completion: nil)


    }

/* StoryboadでMailSignUpToFirstViewを引くため(戻るため)に必要　ボタン
 戻る際の処理が特に必要ないのでメソッドは空です*/
        func BackLogInView(segue: UIStoryboardSegue) {
}
}