Merge branch '40-set-fixed-orientation' into 'master'

Resolve "Set fixed orientation"

Closes #40

See merge request !34

android/gradle.properties

 org.gradle.jvmargs=-Xmx1536M
 android.useAndroidX=true
 android.enableJetifier=true
-app.versionName=0.0.31
-app.versionCode=31
+app.versionName=0.0.32
+app.versionCode=32

lib/main.dart

 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 import 'package:provider/provider.dart';
 
 import 'provider/data.dart';
 import 'screens/home.dart';
 
-void main() => runApp(MyApp());
+void main() {
+  WidgetsFlutterBinding.ensureInitialized();
+  SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp])
+      .then((value) => runApp(MyApp()));
+}
 
 class MyApp extends StatelessWidget {
   @override