Change text reference from Poly to Icosa

Author: andybak

src/ui/landing/LandingPage.js

@@ -128,7 +128,7 @@ export default class LandingPage extends Component {
                 <h3>Discover</h3>
                 <p>
                   Explore images, videos, and 3D models from around the web, all without opening up a new tab. With
-                  media integrations from Sketchfab and Google Poly, you&#39;ll be on your way to creating a scene in no
+                  media integrations from Sketchfab and Icosa Gallery, you&#39;ll be on your way to creating a scene in no
                   time.
                 </p>
               </Callout>