added markup and styles for branding on first view encountered

Should close #148

I went with a really low LOE approach. The CfA Branding is at the top of the first view the user encounters. This should ensure that there is no mistaking Clean as a product or service of HSA. I included the flag tag icon along with the following, very basic copy:

"This is a service provided by Code for America, a 501(c)(3) non-profit organization." - with "Code for America" serving as a link to our homepage.