Add Geotagged Image Support

[jbuckner]

This adds support for dragging geotagged jpg images and puts markers on the map. When you click on the marker, you get a popup with the image.

It uses exif-js for EXIF parsing.

[erik]

Awesome, thanks for the PR!

I won't have time to review until after the weekend but the idea looks cool.

[jbuckner]

I think I got to all of the feedback. I had to add babel-polyfill to support async / await syntax. Man those are nice!

Unfortunately it looks like jshint doesn't support async / await yet so now Travis is failing. I'm seeing what options are available to fix this. It looks like there's a linter called eslint that supports it but I need to dig into this a bit more.

[erik]

Nice! Thanks for addressing our earlier comments.

This looks good to me, I can figure out switching over to eslint as a follow up PR, I've used eslint before and I'm fine migrating this project over to it.

[jbuckner]

Great, thanks! Let me merge master in and fix linting in my branch and I'll push.

[erik]

Oops, sorry for stepping on your toes there with the merge commit. But yeah, the errors at this point are style only, so we should be good to go after that 👍

[jbuckner]

No worries. I just fixed the last few lint issues so the next Travis run should be good.