DodoApp: Public API to fetch allowed networks

Update landing page to communicate with dodo-app backend.

Change-Id: I269ad5150b9203eca9c1c9cc9a8a99b55c583419
diff --git a/core/installer/welcome/app_tmpl.go b/core/installer/welcome/app_tmpl.go
index 252d431..dae56f8 100644
--- a/core/installer/welcome/app_tmpl.go
+++ b/core/installer/welcome/app_tmpl.go
@@ -14,6 +14,7 @@
 const tmplSuffix = ".gotmpl"
 
 type AppTmplStore interface {
+	Types() []string
 	Find(appType string) (AppTmpl, error)
 }
 
@@ -40,6 +41,14 @@
 	return &appTmplStoreFS{apps}, nil
 }
 
+func (s *appTmplStoreFS) Types() []string {
+	var ret []string
+	for t := range s.tmpls {
+		ret = append(ret, t)
+	}
+	return ret
+}
+
 func (s *appTmplStoreFS) Find(appType string) (AppTmpl, error) {
 	if app, ok := s.tmpls[appType]; ok {
 		return app, nil