fix(demo): updated angular flex layout

Author: AnthonyNahas

demo/package-lock.json

@@ -21,7 +21,7 @@
     "@angular/common": "^8.1.3",
     "@angular/compiler": "^8.1.3",
     "@angular/core": "^8.1.3",
-    "@angular/flex-layout": "^6.0.0-beta.18",
+    "@angular/flex-layout": "^8.0.0-beta.26",
     "@angular/forms": "^8.1.3",
     "@angular/material": "^8.1.2",
     "@angular/platform-browser": "^8.1.3",