Removed redundant "const" and "new" assignments & Formatted code. (#58)

veggieseasons/lib/screens/list.dart

@@ -14,7 +14,7 @@ import 'package:veggieseasons/widgets/veggie_card.dart';
 
 class ListScreen extends StatelessWidget {
   List<Widget> _generateVeggieRows(List<Veggie> veggies, Preferences prefs) {
-    final cards = new List<Widget>();
+    final cards = List<Widget>();
 
     for (Veggie veggie in veggies) {
       cards.add(Padding(

veggieseasons/lib/styles.dart

@@ -118,7 +118,7 @@ abstract class Styles {
     Season.autumn: Color(0xff724913),
   };
 
-  static const seasonBorder = const Border(
+  static const seasonBorder = Border(
     top: BorderSide(color: Color(0xff606060)),
     left: BorderSide(color: Color(0xff606060)),
     bottom: BorderSide(color: Color(0xff606060)),

veggieseasons/lib/widgets/close_button.dart

@@ -86,7 +86,7 @@ class CloseButton extends StatefulWidget {
 
   @override
   CloseButtonState createState() {
-    return new CloseButtonState();
+    return CloseButtonState();
   }
 }
 

veggieseasons/lib/widgets/settings_item.dart

@@ -13,7 +13,7 @@ import 'package:veggieseasons/styles.dart';
 //
 // See https://github.com/flutter/flutter/projects/29 for more info.
 
-typedef FutureOr<void> SettingsItemCallback();
+typedef SettingsItemCallback = FutureOr<void> Function();
 
 class SettingsNavigationIndicator extends StatelessWidget {
   const SettingsNavigationIndicator({Key key}) : super(key: key);
@@ -77,7 +77,7 @@ class SettingsItem extends StatefulWidget {
   final SettingsItemCallback onPress;
 
   @override
-  State<StatefulWidget> createState() => new SettingsItemState();
+  State<StatefulWidget> createState() => SettingsItemState();
 }
 
 class SettingsItemState extends State<SettingsItem> {