Mobile app initial implementation.

Closes #3 (closed)

lib/src/screens/home.dart

@@ -17,7 +17,30 @@ class Home extends StatefulWidget {
   _HomeState createState() => _HomeState();
 }
 
+const hosts = [
+  'https://rosengeorgiev.dev.vereign.com',
+  'https://borisdimitrov.dev.vereign.com',
+  'https://app.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',
+  'https://igormarkin.dev.vereign.com',
+  'https://mikhaildorokhovich.dev.vereign.com',
+  'https://sashailieva.dev.vereign.com',
+  'https://alexanderholodov.dev.vereign.com',
+  'https://olguncengiz.dev.vereign.com',
+  'https://viktorpopov.dev.vereign.com',
+  'https://kalincanov.dev.vereign.com',
+  'https://alexeykuklin.dev.vereign.com'
+];
+
 class _HomeState extends State<Home> {
+  String _host = Config.appFlavor == Flavor.DEVELOPMENT ? hosts[0] : APP_HOST;
+
   @override
   initState() {
     super.initState();
@@ -77,7 +100,7 @@ class _HomeState extends State<Home> {
   }
 
   openVereign() {
-    FlutterWebBrowser.openWebPage(url: APP_HOST, androidToolbarColor: Color(0xFFd51d32));
+    FlutterWebBrowser.openWebPage(url: _host, androidToolbarColor: Color(0xFFd51d32));
   }
 
   startOAuth() {
@@ -100,29 +123,63 @@ class _HomeState extends State<Home> {
   }
 
 
+
   @override
   Widget build(BuildContext context) {
+    var children = <Widget>[
+      _urlButton(context, "Open Dashboard", openVereign),
+      _urlButton(context, "Authorize with Vereign", startOAuth)
+    ];
+
+    if (Config.appFlavor == Flavor.DEVELOPMENT) {
+      children.add(
+        wrapInContainer(
+          DropdownButton<String>(
+            value: _host,
+            onChanged: (String newValue) {
+              setState(() {
+                _host = newValue;
+              });
+            },
+            items: hosts
+                .map<DropdownMenuItem<String>>((String value) {
+                  return DropdownMenuItem<String>(
+                    value: value,
+                    child: Text(value),
+                  );
+                })
+                .toList(),
+            )
+        )
+      );
+    }
+
     return Scaffold(
         body: SafeArea(
             child: SingleChildScrollView(
                 child: Column(
                   mainAxisAlignment: MainAxisAlignment.center,
                   crossAxisAlignment: CrossAxisAlignment.stretch,
-                  children: <Widget>[
-                    _urlButton(context, "Open Dashboard", openVereign),
-                    _urlButton(context, "Authorize with Vereign", startOAuth),
-                  ]
+                  children: children
                 ))));
   }
-  Widget _urlButton(BuildContext context, String title, listener) {
+
+  Widget wrapInContainer(Widget widget) {
     return Container(
-        padding: EdgeInsets.all(20.0),
-        child: FlatButton(
+      padding: EdgeInsets.all(20.0),
+      child: widget,
+    );
+  }
+
+  Widget _urlButton(BuildContext context, String title, listener) {
+    return wrapInContainer(
+        FlatButton(
           color: Theme.of(context).primaryColor,
           textColor: Colors.white,
           padding: const EdgeInsets.symmetric(horizontal: 50.0, vertical: 15.0),
           child: Text(title),
           onPressed: listener
-        ));
+        )
+    );
   }
 }
\ No newline at end of file