Mobile app initial implementation.

Closes #3 (closed)

lib/src/screens/home.dart

@@ -8,9 +8,10 @@ import 'dart:convert';
 import '../../config.dart';
 
 class Home extends StatefulWidget {
-  Home({@required this.mode, @required this.invokerURL, @required this.setMode});
+  Home({@required this.mode, @required this.invokerURL, @required this.setMode, @required this.host});
   final String mode;
   final String invokerURL;
+  final String host;
   final void Function(String) setMode;
 
   @override
@@ -18,12 +19,12 @@ class Home extends StatefulWidget {
 }
 
 const hosts = [
+  'https://demo1.vereign.com',
+  'https://demo2.vereign.com',
   'https://rosengeorgiev.dev.vereign.com',
   'https://borisdimitrov.dev.vereign.com',
   'https://integration.vereign.com',
   'https://staging.vereign.com',
-  'https://demo1.vereign.com',
-  'https://demo2.vereign.com',
   'https://damyanmitev.dev.vereign.com',
   'https://gospodinbodurov.dev.vereign.com',
   'https://alexeylunin.dev.vereign.com',
@@ -83,14 +84,21 @@ class _HomeState extends State<Home> {
     // this method IS called when parent widget passes new "props"
     // unlike React, this method IS called _before_ the build
     // unlike React, this method ISN'T called after setState()
+
+    if (widget.host != oldWidget.host && widget.host != null) {
+      setState(() {
+        _host = widget.host;
+      });
+    }
+
     if (widget.mode != oldWidget.mode) {
       showMode(widget.mode);
     }
+
     super.didUpdateWidget(oldWidget);
   }
 
   showMode(mode) {
-    log(mode);
     if (mode == "app") {
       openVereign();
     } else if (mode == "oauth") {