Pholio tile to home page and mock to show first image

Summary:
Pholio tile to show up on home page

First image is shown at mock page.

Test Plan: Pholio app shows up on home page. First image is shown at mock page.

Reviewers: epriestley

CC: aran, Korvin

Maniphest Tasks: T2356

Differential Revision: https://secure.phabricator.com/D4553