CSS and Image add

Hey, everyone. I've added a bootstrap template (flatly), and I've customized a few things in the application.css page--make sure to review these when you're ready to do more CSS. This updates the nav-bar colors, and it customizes (I hope) some side banners, like the asapmetro.org site. Same colors.

I also added a picture of an Oregon Humane Society to the assets page. It's the same size as the asapmetro.org header pic. But it's not a requirement. I just thought you might like a picture to include. I'm not sure what logo we'll end up using.