Added Gem debugger

Remove page controller and views
Landing page is signup page or quote index

Added routes login & logout, updated root path
config/routes.rb

Added methods logout and login for userscontroller
Added missing dependencies to models:
app/models/customer.rb
app/models/product.rb
app/models/products_quote.rb
app/models/quote.rb
app/models/user.rb

Updated form to include placeholder
app/views/users/_form.html.erb

Created form for sign in
app/views/users/_form_signin.html.erb

Updated index to display signin
app/views/users/index.html.erb

Added link to signin on signup page
app/views/users/new.html.erb