Continue to fix deprecation warnings

lib/ui/routes/create_account_route.dart

@@ -174,9 +174,7 @@ class __CreateAccountRouteBodyState extends State<_CreateAccountRouteBody> {
 
               // Submit button
               Center(
-                child: RaisedButton(
-                  color: Colors.blue,
-                  textColor: Colors.white,
+                child: ElevatedButton(
                   onPressed: _submitForm,
                   child: Text("Submit"),
                 ),

lib/ui/routes/forgot_password_route.dart

@@ -61,7 +61,7 @@ class _ResetPasswordBodyState extends SafeState<_ResetPasswordBody> {
 
   /// Step 3b - Answer security questions
   List<String> _questions;
-  var _questionsControllers = List<TextEditingController>();
+  var _questionsControllers = <TextEditingController>[];
 
   List<String> get _answers =>
       _questionsControllers.map((f) => f.text).toList();

lib/ui/routes/login_route.dart

@@ -127,7 +127,7 @@ class _LoginRouteState extends State<LoginRoute> {
               padding: EdgeInsets.all(8.0),
               child: _loading
                   ? CircularProgressIndicator()
-                  : RaisedButton(
+                  : ElevatedButton(
                       child: Text(tr("Sign in")),
                       onPressed: valid ? () => _submitForm(context) : null,
                     ),

lib/ui/routes/main_route/main_route.dart

@@ -37,7 +37,7 @@ mixin MainRoute implements StatefulWidget {}
 
 /// Public interface of home controller
 abstract class MainController extends State<MainRoute> {
-  final _pagesStack = List<PageInfo>();
+  final _pagesStack = <PageInfo>[];
 
   /// Default page of the application
   PageInfo get defaultPage;

lib/ui/routes/password_reset_route.dart

@@ -77,7 +77,7 @@ class __PasswordResetBodyState extends SafeState<_PasswordResetBody> {
         mainAxisSize: MainAxisSize.min,
         children: <Widget>[
           Text(tr("You can choose a new password.")),
-          OutlineButton(
+          OutlinedButton(
             onPressed: _changePassword,
             child: Text(tr("Choose a new password")),
           )
@@ -97,7 +97,7 @@ class __PasswordResetBodyState extends SafeState<_PasswordResetBody> {
             tr("Congratulations! Your password has now been successfully changed!"),
             textAlign: TextAlign.center,
           ),
-          OutlineButton(
+          OutlinedButton(
             onPressed: _quitScreen,
             child: Text(tr("Login")),
           )