Added thumbnail for blank pages

Signed-off-by: boris <boris.karastanev@progress.com>

consts/pages-backup-data.js

@@ -10,7 +10,8 @@ BackupData.fallback = [
         version: "3.1.4",
         gitUrl: "https://github.com/NativeScript/nativescript-page-templates/tree/master/blank",
         templateFlavor: "JavaScript",
-        type: "Page template"
+        type: "Page template",
+        thumbnail: "file-o"
     },
     {
         name: "tns-page-login",
@@ -40,7 +41,8 @@ BackupData.fallback = [
         version: "3.1.4",
         gitUrl: "https://github.com/NativeScript/nativescript-page-templates-ts/tree/master/blank",
         templateFlavor: "TypeScript",
-        type: "Page template"
+        type: "Page template",
+        thumbnail: "file-o"
     },
     {
         name: "tns-page-login-ts",
@@ -69,7 +71,8 @@ BackupData.fallback = [
         version: "3.1.4",
         gitUrl: "https://github.com/NativeScript/nativescript-page-templates-ng/tree/master/blank",
         templateFlavor: "Angular & TypeScript",
-        type: "Page template"
+        type: "Page template",
+        thumbnail: "file-o"
     },
     {
         name: "tns-page-login-ng",

test/test-page-backup.ts

@@ -21,6 +21,7 @@ describe("Page backup data", () => {
                         expect(item).to.have.property("version");
                         expect(item).to.have.property("templateFlavor");
                         expect(item).to.have.property("type");
+                        expect(item).to.have.property("thumbnail");
                     });
                 });
         });