Update gems to the latest versions.

Gemfile

@@ -1,12 +1,9 @@
-# Ruby Gems for building and testing Bootstrap
-# Run `grunt update-gemfile-lock` to update to the latest compatible versions
-
 source 'https://rubygems.org'
 
 group :development, :test do
-  gem 'jekyll', '~> 3.0.1'
-  gem 'jekyll-redirect-from', '~> 0.9.0'
+  gem 'jekyll', '~> 3.1.0'
+  gem 'jekyll-redirect-from', '~> 0.9.1'
   gem 'jekyll-sitemap', '~> 0.9.0'
-  gem 'sass', '~> 3.4.19'
+  gem 'sass', '~> 3.4.21'
   gem 'scss_lint', '~> 0.44.0'
 end

Gemfile.lock

@@ -4,7 +4,7 @@ GEM
     colorator (0.1)
     ffi (1.9.10)
     ffi (1.9.10-x64-mingw32)
-    jekyll (3.0.2)
+    jekyll (3.1.0)
       colorator (~> 0.1)
       jekyll-sass-converter (~> 1.0)
       jekyll-watch (~> 1.1)
@@ -42,10 +42,10 @@ PLATFORMS
   x64-mingw32
 
 DEPENDENCIES
-  jekyll (~> 3.0.1)
-  jekyll-redirect-from (~> 0.9.0)
+  jekyll (~> 3.1.0)
+  jekyll-redirect-from (~> 0.9.1)
   jekyll-sitemap (~> 0.9.0)
-  sass (~> 3.4.19)
+  sass (~> 3.4.21)
   scss_lint (~> 0.44.0)
 
 BUNDLED WITH