flutter pub upgrade (#178)

provider_counter/lib/main.dart

@@ -17,7 +17,7 @@ void main() {
       // Initialize the model in the builder. That way, Provider
       // can own Counter's lifecycle, making sure to call `dispose`
       // when not needed anymore.
-      builder: (context) => Counter(),
+      create: (context) => Counter(),
       child: MyApp(),
     ),
   );

provider_counter/pubspec.lock

@@ -63,7 +63,7 @@ packages:
       name: cupertino_icons
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.2"
+    version: "0.1.3"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -122,7 +122,7 @@ packages:
       name: provider
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.1.0+1"
+    version: "3.2.0"
   quiver:
     dependency: transitive
     description:

provider_counter/test/widget_test.dart

@@ -12,7 +12,7 @@ void main() {
     // Build our app, provide it with a model, and trigger a frame.
     await tester.pumpWidget(
       ChangeNotifierProvider(
-        builder: (context) => Counter(),
+        create: (context) => Counter(),
         child: MyApp(),
       ),
     );