Fix Observe logo header in nav drawer

[LanesGood]

The Observe logo and text in the navigation drawer are missing. Where did the logo go??

This PR:

• adds logo back
• fix font issues introduced by current RN version

Current edit-ways branch:

[LanesGood]

@geohacker at one point the Observe Logo showed up in the drawer - now it does not. It looks like it was previously stored in the iconfont, or at least wound up in Android folders and iOS ones. This may require adding the SVG to the repo, then re-running the font generation and reuploading again to the /observe-icon-font repo :(

I can investigate further tomorrow if needed.

[geohacker]

Oh nice catch @LanesGood. I think this logo was an image asset pulled in with the Image styled component via a URI. We may have blown this away during our updates to icons. Adding this back to the assets folder should do the trick I think.

[geohacker]

@LanesGood I just added the icons back. This was getting blown away because of our update-icons.sh script and we should figure out a way to manage that properly, I'll ticket that separately.