Prepare layout and home page for Bootstap
Use Bootstrap
Add some Bootstrap styling
Add some typographic Bootstrap styling
Style logo
Convert to partials
Add footer
Style footer
Convert to SCSS nesting syntax
Use names and variables for colors

This changes hex codes to built-in color names (e.g. white), Bootstrap-defined color variables (e.g. $gray), and variables defined by us (e.g. $grayMediumLight).
Implement named routes
Make Guard keep working smoothly when config/routes.rb is changed
Use URLs like .../help instead of .../static_pages/help
Use named routes in partials
Make home page work
Refactor spec, with support utility
Add sign-up page
Link to new sign-up page from home
Merge branch 'filling-in-layout'