5.1.1 prepare header for Bootstrap, add rails image
Fix extra space in home.html.erb, actually include rails image
5.1.2 add sass stylesheet, precompile in application config, and add sass and bootstrap to gemfile
5.1.3 add partials to clean up custom.css, include partials in application
5.2 dry out the custom sass with nesting and variables for color
Add back titles to each page except home, reduce spacing on home.html.erb
5.3 name routes, link to routes instead of stubs, simplify rspec
5.4 generate new users controller, map route to signup, link button to new signup route