Bug Description
A clear and concise description of what the bug is and how to reproduce it.

Steps to reproduce for using ruby:

1.clone the template (from github)
2. Update gem file of sass library into saasc
3. execute this cmd : Gem install bunder
4. execute this cmd : bundle installed
5. execute this cmd : bundle exec middleman build
6. screen.css.scss file are showing some error when build , so remove this: // and add /* */ only inside the css class
7. after fixes of scss file again build it and then
8. execute this cmd : bundle exec middleman build

once server started , the ui look like collapsed screen shot were attached below

Using docker

the following issue were if use docker option to build it in windows machine.

I followed the instructions as per the Docker integration and found I was not able to publish a version of my Slate documentation as there were line endings issues, "/usr/bin/env: ‘bash\r’: No such file or directory" when tried with a slightly different methodology there were issues about Gemfiles and bundle not existing, which I understand to be Ruby specific. Is there a way to publish without downloading Ruby

Always docker steps:

Screenshots
If applicable, add screenshots to help explain your problem.
If using ruby to do we are getting build issue and UI looks like collapsed.

Browser (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Last upstream Slate commit (run git log --author="\(Robert Lord\)\|\(Matthew Peveler\)\|\(Mike Ralphson\)" | head -n 1):
Put the commit hash here