use HAML instead of ERB

Signed-off-by: Zeljko <zeljko@zwr.fi>
main page

Signed-off-by: Zeljko <zeljko@zwr.fi>
rails g scaffold User

This generate scaffold user, same one that will become Devise
model in a few commits. However, we want Rails to generate the
controller and views, so we do not have to.

Signed-off-by: Zeljko <zeljko@zwr.fi>
add Device and its model User

Do this:
  rails g devise:install
  rails g devise User

But before and after that perform steps from
https://github.com/zmilojko/devise_scaffold so to merge devise
features of User with normal scaffold features.

All tests passed.

Signed-off-by: Zeljko <zeljko@zwr.fi>
all views haml not erb

One layout was still erb.

Signed-off-by: Zeljko <zeljko@zwr.fi>