Compass Style with Ruby 2.2.3 and Rails 4.2.4

I'm having trouble finding any help with installing compass with Ruby on Rails.

I have searched high and low on the web but I'm struggling to get compass recognised within my application.

Sass is working great but compass is just not there.

Here's my current setup:

Ruby 2.2.3 Rails 4.2.4

Gemfile

gem 'compass', '1.0.0'

group :assets do
  gem 'compass-rgbapng'
  gem 'sass-rails', '~> 5.0.4'
  gem "compass-rails", '2.0.5'
end

I have just downgraded compass to 1.0.0 from 1.0.3 as I believed this could have been part of the issue, but no luck.

I have changed: application.css to application.scss and included the following:

@import 'compass'

I then receive the following in browser when running the rails server

File to import not found or unreadable: compass.

I hope i'm missing a small step or has compass integration been abandoned?

If this can't be resolved, would you recommend moving to Bourbon? (Please only answer this question if Compass is an absolute no go with Rails).

Many thanks.