Update to jekyll-sitemap v0.6.1

https://github.com/jekyll/jekyll-sitemap/releases/tag/v0.6.1
https://github.com/jekyll/jekyll-sitemap/compare/v0.6.0...v0.6.1

:chocolate_bar:
Bump coffee-script dependency to 1.0.1
Update to jekyll-sitemap v0.6.2

Release: https://github.com/jekyll/jekyll-sitemap/releases/tag/v0.6.2
Diff since v0.6.1: https://github.com/jekyll/jekyll-sitemap/compare/v0.6.1...v0.6.2
Diff since v0.6.0: https://github.com/jekyll/jekyll-sitemap/compare/v0.6.0...v0.6.2
Bump jekyll-sitemap to v0.6.3

This release is about backwards-compatibility for versions of Jekyll before 2.5.0.
Release: https://github.com/jekyll/jekyll-sitemap/releases/tag/v0.6.3
Diff: https://github.com/jekyll/jekyll-sitemap/compare/v0.6.2...v0.6.3
Add jekyll new and jekyll build steps to the script/cibuild.
Merge pull request #96 from github/bump-coffee-script

Bump coffee-script dependency to 1.0.1
Merge pull request #100 from parkr/sitemap-0.6.2

Update to jekyll-sitemap v0.6.3
Merge pull request #101 from parkr/build-a-jekyll-site

Add jekyll new and jekyll build steps to the script/cibuild.
Bump Jekyll to v2.5.0

Release post: http://jekyllrb.com/news/2014/11/05/jekylls-midlife-crisis-jekyll-turns-2-5-0/
GitHub Release: https://github.com/jekyll/jekyll/releases/tag/v2.5.0
Diff: https://github.com/jekyll/jekyll/compare/v2.4.0...v2.5.0

Security should be happy with this: all path sanitation is centralized now.
See https://github.com/jekyll/jekyll/pull/2882 for more info.

Also be sure to set JEKYLL_NO_BUNDLER_REQUIRE=true in your environment.