Main OnBoading Screen: Add some padding

+ some color to the input box

I would have assumed that the background color would have come by
default.

lib/app.dart

@@ -26,6 +26,8 @@ class JournalApp extends StatelessWidget {
       theme: new ThemeData(
         brightness: Brightness.light,
         primaryColor: Color(0xFF66bb6a),
+        primaryColorLight: Color(0xFF98ee99),
+        primaryColorDark: Color(0xFF338a3e),
         accentColor: Color(0xff6d4c41),
       ),
       navigatorObservers: <NavigatorObserver>[observer],

lib/screens/onboarding_screens.dart

@@ -124,15 +124,27 @@ class OnBoardingGitUrlState extends State<OnBoardingGitUrl> {
       mainAxisAlignment: MainAxisAlignment.center,
       crossAxisAlignment: CrossAxisAlignment.center,
       children: <Widget>[
-        Text(
-          'Enter the Git SSH URL',
-          textAlign: TextAlign.center,
-          style: Theme.of(context).textTheme.display1,
+        Padding(
+          padding: const EdgeInsets.all(8.0),
+          child: Text(
+            'Enter the Git SSH URL',
+            textAlign: TextAlign.center,
+            style: Theme.of(context).textTheme.display1,
+          ),
         ),
-        inputForm,
-        RaisedButton(
-          child: Text("Next"),
-          onPressed: formSubmitted,
+        Padding(
+          padding: const EdgeInsets.all(8.0),
+          child: new Container(
+            color: Theme.of(context).primaryColorLight,
+            child: inputForm,
+          ),
+        ),
+        Padding(
+          padding: const EdgeInsets.all(8.0),
+          child: RaisedButton(
+            child: Text("Next"),
+            onPressed: formSubmitted,
+          ),
         )
       ],
     );