Add resiliency to testimonial component

[ann-kilzer]

The testimonial component might show up empty if the tweet has been deleted. See here: #192

It would be great if we could detect this and be more robust.

[renderf0x]

I wish they'd merge this CR, as this could be easily used for this:
tonickkozlov/vue-tweet-embed#58

[renderf0x]

Blocked on the design from @thehamspecial for the testimonials area / page, as that will define what the component should do (render a random different tweet? not render?) based on how many are in the layout, etc.

I think this will need to be a fresh component for Tweets instead of the lib we're using, but that should be easy enough given that Twitter's embed lib looks pretty straightforward.

[renderf0x]

Working off of @thehamspecial 's current mock of the page to add the new styling to this component too:
https://www.figma.com/proto/kdgcV9gd3cOeiSgoXY6VLM/Find-a-Doc?node-id=4%3A16&scaling=fit-width&page-id=0%3A1&hotspot-hints=0&hide-ui=1

@thehamspecial - do you have a mock for what you'd want this Twitter component to look like on a small screen size?

[thehamspecial]

@renderf0x Yup, here's the layout on small screens.

Here's the desktop view. Let me know if you have feedback!

[renderf0x]

Looks great @thehamspecial - will work on getting the Twitter portion up and running.