added nav elements to application layout
added sign-up button and rails logo to homepage
installed bootstrap
added custom scss styles to application layout
added custom typography rules to application layout
implemented Sass syntax in application css
create partials for footer, header, and shim
introduced Sass variables into application css
fixed error in application css -- added missing semicolon
add named routes for static pages to route file
add named routes to header and footer partials
refactored static page specs -- made DRYer using subject variable and before helper method
Create user controller and signup page for new users