App Drawer: Implement the share button

It's very basic, but it's a decent start.

lib/widgets/app_drawer.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:journal/state_container.dart';
+import 'package:share/share.dart';
 
 class AppDrawer extends StatelessWidget {
   @override
@@ -46,8 +47,7 @@ class AppDrawer extends StatelessWidget {
             title: Text('Share App'),
             onTap: () {
               Navigator.pop(context);
-              // Update the state of the app
-              // ...
+              Share.share('Checkout GitJournal https://gitjournal.io/');
             },
           ),
           ListTile(

pubspec.lock

@@ -345,6 +345,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.0.1"
+  share:
+    dependency: "direct main"
+    description:
+      name: share
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.6.0+1"
   shared_preferences:
     dependency: "direct main"
     description:

pubspec.yaml

@@ -17,6 +17,7 @@ dependencies:
   package_info: ^0.3.2+1
   http: ^0.12.0+1
   badges: ^0.0.6
+  share: ^0.6.0+1
 
 dev_dependencies:
   flutter_launcher_icons: "^0.7.0"