remove duplicate array in redirect_from directive

[parkr]

This PR fixes a build failure I saw locally with the latest version of github-pages.

  Liquid Exception: undefined method `end_with?' for ["/cs-engine/release-notes/prior-release-notes/"]:Array in 404.md
  bundler: failed to load command: jekyll (/Users/parkr/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/bin/jekyll)
  NoMethodError: undefined method `end_with?' for ["/cs-engine/release-notes/prior-release-notes/"]:Array

[johndmulhausen]

Goodness gracious, @parkr is opening a PR against our docs! Welcome, we are big fans of Jekyll around here. While I have you: Bump Rouge to 2.0! @jneen added Dockerfile lexer support! :)

Okay, the toc.yaml change looks great.

The problem with pinning to GH-Pages 121, however, is that we are using starefossen/github-pages to synchronize our Dockerfile's GH-Pages environment and the Gemfile's GH-Pages environment, and the latest versions-specific tag on that repo is 112:

• https://hub.docker.com/r/starefossen/github-pages/tags/
• https://github.com/docker/docker.github.io/blob/docs-base/Dockerfile
• https://github.com/docker/docker.github.io/blob/master/Gemfile

If there's a better way to get Dockerized GitHub Pages then I'd love to use the latest, but I'm nervous of having the production environment (specified in the Dockerfile) lose sync with Gemfile we are using to author locally, set up staging on Netlify, etc.

Long story -- the TL;DR is would you mind backing out your Gemfile change?

[parkr]

Bump Rouge to 2.0! @jneen added Dockerfile lexer support! :)

Haha, we have it filed (jekyll/jekyll#5556) but we hit a bit of a compatibility roadblock under SemVer: jekyll/jekyll#5230 (comment)

we are using starefossen/github-pages to synchronize our Dockerfile's GH-Pages environment and the Gemfile's GH-Pages environment, and the latest versions-specific tag on that repo is 112

Perhaps we can work together to automatically release a new version whenever we push a new Release to github/pages-gem. I'll open an issue.

Long story -- the TL;DR is would you mind backing out your Gemfile change?

Happy to! I will remove the commit. 👍

[johndmulhausen]

@parkr I would love to work with you on Dockerizing GitHub Pages. We're pretty good at crafting Docker files here. ;)

[johndmulhausen]

@parkr Let me know when your issue is opened.