Update dependencies.

Gemfile

@@ -1,8 +1,8 @@
 source 'https://rubygems.org'
 
 group :development, :test do
-  gem 'jekyll', '~> 3.3.1'
-  gem 'jekyll-redirect-from', '~> 0.12.0'
-  gem 'jekyll-sitemap', '~> 0.12.0'
-  gem 'scss_lint', '~> 0.51.0'
+  gem 'jekyll', '~> 3.4.0'
+  gem 'jekyll-redirect-from', '~> 0.12.1'
+  gem 'jekyll-sitemap', '~> 1.0.0'
+  gem 'scss_lint', '~> 0.52.0'
 end

Gemfile.lock

@@ -4,9 +4,9 @@ GEM
     addressable (2.5.0)
       public_suffix (~> 2.0, >= 2.0.2)
     colorator (1.1.0)
-    ffi (1.9.14)
+    ffi (1.9.17)
     forwardable-extended (2.6.0)
-    jekyll (3.3.1)
+    jekyll (3.4.0)
       addressable (~> 2.4)
       colorator (~> 1.0)
       jekyll-sass-converter (~> 1.0)
@@ -17,15 +17,15 @@ GEM
       pathutil (~> 0.9)
       rouge (~> 1.7)
       safe_yaml (~> 1.0)
-    jekyll-redirect-from (0.12.0)
+    jekyll-redirect-from (0.12.1)
       jekyll (~> 3.3)
     jekyll-sass-converter (1.5.0)
       sass (~> 3.4)
-    jekyll-sitemap (0.12.0)
+    jekyll-sitemap (1.0.0)
       jekyll (~> 3.3)
     jekyll-watch (1.5.0)
       listen (~> 3.0, < 3.1)
-    kramdown (1.13.1)
+    kramdown (1.13.2)
     liquid (3.0.6)
     listen (3.0.8)
       rb-fsevent (~> 0.9, >= 0.9.4)
@@ -36,23 +36,23 @@ GEM
     public_suffix (2.0.5)
     rake (12.0.0)
     rb-fsevent (0.9.8)
-    rb-inotify (0.9.7)
+    rb-inotify (0.9.8)
       ffi (>= 0.5.0)
     rouge (1.11.1)
     safe_yaml (1.0.4)
     sass (3.4.23)
-    scss_lint (0.51.0)
+    scss_lint (0.52.0)
       rake (>= 0.9, < 13)
       sass (~> 3.4.20)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  jekyll (~> 3.3.1)
-  jekyll-redirect-from (~> 0.12.0)
-  jekyll-sitemap (~> 0.12.0)
-  scss_lint (~> 0.51.0)
+  jekyll (~> 3.4.0)
+  jekyll-redirect-from (~> 0.12.1)
+  jekyll-sitemap (~> 1.0.0)
+  scss_lint (~> 0.52.0)
 
 BUNDLED WITH
    1.13.6