Allow setting git signature

pass/Controllers/GitConfigSettingTableViewController.swift

@@ -0,0 +1,39 @@
+//
+//  GitConfigSettingTableViewController.swift
+//  pass
+//
+//  Created by Yishi Lin on 10/4/17.
+//  Copyright © 2017 Yishi Lin. All rights reserved.
+//
+
+import UIKit
+import SwiftyUserDefaults
+
+class GitConfigSettingTableViewController: UITableViewController {
+    
+    @IBOutlet weak var nameTextField: UITextField!
+    @IBOutlet weak var emailTextField: UITextField!
+    
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        tableView.rowHeight = UITableViewAutomaticDimension
+        nameTextField.text = Defaults[.gitName]
+        emailTextField.text = Defaults[.gitEmail]
+    }
+    
+    override func shouldPerformSegue(withIdentifier identifier: String, sender: Any?) -> Bool {
+        print("test should perform \(identifier)")
+        if identifier == "saveGitConfigSettingSegue" {
+            guard let name = nameTextField.text, !name.isEmpty else {
+                Utils.alert(title: "Cannot Save", message: "Please set name first.", controller: self, completion: nil)
+                return false
+            }
+            guard let email = emailTextField.text, !email.isEmpty else {
+                Utils.alert(title: "Cannot Save", message: "Please set email first.", controller: self, completion: nil)
+                return false
+            }
+        }
+        return true
+    }
+}
+