Ported the cutup HTML and CSS over to the web app.

We are going to be using only ONE stylesheet for the entire web app. It
is located at: /app/assets/stylesheets/screen.scss - I literally copied
and pasted over the stylesheet I made for the cutup so that should be
all set for all screens in there.

I have ported the HTML for the application layout
(views/layouts/application.html.erb), the home page, and sign in page.

Regarding the sign in, sign up and home page, I had created custom
routes in the routes.rb config file. This way, the link: /signup will
point to the user/new controller/action, the /login will point to the
session/new controller/action, and the / (default page) will point to
home/index.

I have also added some gem files that you will have to install on your
machine by running sudo bundle install on your command line inside the
whatsapp directory.