diff --git a/Gemfile b/Gemfile
index ba9baea..134540f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,14 +1,14 @@
 source 'https://rubygems.org'
 
 gem 'jekyll'
-gem 'jekyll-assets'
+gem 'jekyll-assets', '>= 2.2.5'
 gem 'jekyll-paginate'
 gem 'jekyll-tagging'
 gem 'jekyll-seo-tag'
-gem 'jekyll-sitemap'
+gem 'jekyll-sitemap', '>= 0.12.0'
 gem 'bootstrap-sass'
 gem 'font-awesome-sass'
-gem 'html-proofer'
+gem 'html-proofer', '>= 3.4.0'
 gem 'sass'
 gem 'uglifier'
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 88c7358..512d499 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,12 +2,8 @@ GEM
   remote: https://rubygems.org/
   remote: https://rails-assets.org/
   specs:
-    activesupport (5.0.1)
-      concurrent-ruby (~> 1.0, >= 1.0.2)
-      i18n (~> 0.7)
-      minitest (~> 5.1)
-      tzinfo (~> 1.1)
-    addressable (2.4.0)
+    addressable (2.8.0)
+      public_suffix (>= 2.0.2, < 5.0)
     algoliasearch (1.10.0)
       httpclient (~> 2.7.1)
       json (>= 1.5.1)
@@ -29,98 +25,113 @@ GEM
     bootstrap-sass (3.3.6)
       autoprefixer-rails (>= 5.2.1)
       sass (>= 3.3.4)
-    colorator (0.1)
-    colored (1.2)
-    concurrent-ruby (1.0.2)
-    ethon (0.10.1)
-      ffi (>= 1.3.0)
+    colorator (1.1.0)
+    concurrent-ruby (1.1.9)
+    em-websocket (0.5.2)
+      eventmachine (>= 0.12.9)
+      http_parser.rb (~> 0.6.0)
+    ethon (0.14.0)
+      ffi (>= 1.15.0)
+    eventmachine (1.2.7)
     execjs (2.6.0)
-    extras (0.1.0)
+    extras (0.3.0)
       forwardable-extended (~> 2.5)
-    fastimage (2.0.0)
-      addressable (~> 2)
-    ffi (1.9.10)
+    fastimage (2.2.4)
+    ffi (1.15.3)
     font-awesome-sass (4.6.2)
       sass (>= 3.2)
     forwardable-extended (2.6.0)
-    html-proofer (3.4.0)
-      activesupport (>= 4.2, < 6.0)
+    html-proofer (3.19.2)
       addressable (~> 2.3)
-      colored (~> 1.2)
-      mercenary (~> 0.3.2)
-      nokogiri (~> 1.5)
+      mercenary (~> 0.3)
+      nokogumbo (~> 2.0)
       parallel (~> 1.3)
-      typhoeus (~> 0.7)
+      rainbow (~> 3.0)
+      typhoeus (~> 1.3)
       yell (~> 2.0)
+    http_parser.rb (0.6.0)
     httpclient (2.7.2)
-    i18n (0.7.0)
-    jekyll (3.1.2)
-      colorator (~> 0.1)
+    i18n (0.9.5)
+      concurrent-ruby (~> 1.0)
+    jekyll (3.9.1)
+      addressable (~> 2.4)
+      colorator (~> 1.0)
+      em-websocket (~> 0.5)
+      i18n (~> 0.7)
       jekyll-sass-converter (~> 1.0)
-      jekyll-watch (~> 1.1)
-      kramdown (~> 1.3)
-      liquid (~> 3.0)
+      jekyll-watch (~> 2.0)
+      kramdown (>= 1.17, < 3)
+      liquid (~> 4.0)
       mercenary (~> 0.3.3)
-      rouge (~> 1.7)
+      pathutil (~> 0.9)
+      rouge (>= 1.7, < 4)
       safe_yaml (~> 1.0)
-    jekyll-assets (2.2.5)
-      extras (~> 0.1)
+    jekyll-assets (2.4.0)
+      concurrent-ruby (~> 1.0)
+      extras (~> 0.2)
       fastimage (~> 2.0, >= 1.8)
       jekyll (~> 3.1, >= 3.0)
       pathutil (>= 0.8)
-      sprockets (~> 3.3)
+      rack (~> 1.6)
+      sprockets (~> 3.3, < 3.8)
     jekyll-paginate (1.1.0)
-    jekyll-sass-converter (1.4.0)
+    jekyll-sass-converter (1.5.2)
       sass (~> 3.4)
     jekyll-seo-tag (2.0.0)
       jekyll (~> 3.1)
-    jekyll-sitemap (0.11.0)
-      addressable (~> 2.4.0)
+    jekyll-sitemap (1.4.0)
+      jekyll (>= 3.7, < 5.0)
     jekyll-tagging (1.0.1)
       ruby-nuggets
-    jekyll-watch (1.3.1)
+    jekyll-watch (2.2.1)
       listen (~> 3.0)
     json (1.8.3)
-    kramdown (1.10.0)
-    liquid (3.0.6)
-    listen (3.0.6)
-      rb-fsevent (>= 0.9.3)
-      rb-inotify (>= 0.9.7)
+    kramdown (2.3.1)
+      rexml
+    liquid (4.0.3)
+    listen (3.5.1)
+      rb-fsevent (~> 0.10, >= 0.10.3)
+      rb-inotify (~> 0.9, >= 0.9.10)
     mercenary (0.3.6)
-    mini_portile2 (2.1.0)
-    minitest (5.10.1)
-    nokogiri (1.6.8)
-      mini_portile2 (~> 2.1.0)
-      pkg-config (~> 1.1.7)
+    mini_portile2 (2.5.3)
+    nokogiri (1.11.7)
+      mini_portile2 (~> 2.5.0)
+      racc (~> 1.4)
+    nokogumbo (2.0.5)
+      nokogiri (~> 1.8, >= 1.8.4)
     nuggets (1.0.0)
-    parallel (1.10.0)
-    pathutil (0.9.0)
+    parallel (1.20.1)
+    pathutil (0.16.2)
       forwardable-extended (~> 2.6)
-    pkg-config (1.1.7)
-    rack (1.6.4)
+    public_suffix (4.0.6)
+    racc (1.5.2)
+    rack (1.6.13)
     rails-assets-jquery (2.2.3)
+    rainbow (3.0.0)
     rake (11.2.2)
-    rb-fsevent (0.9.7)
-    rb-inotify (0.9.7)
-      ffi (>= 0.5.0)
-    rouge (1.10.1)
+    rb-fsevent (0.11.0)
+    rb-inotify (0.10.1)
+      ffi (~> 1.0)
+    rexml (3.2.5)
+    rouge (3.26.0)
     ruby-nuggets (1.0.0)
       nuggets (= 1.0.0)
-    safe_yaml (1.0.4)
-    sass (3.4.22)
-    sprockets (3.6.0)
+    safe_yaml (1.0.5)
+    sass (3.7.4)
+      sass-listen (~> 4.0.0)
+    sass-listen (4.0.0)
+      rb-fsevent (~> 0.9, >= 0.9.4)
+      rb-inotify (~> 0.9, >= 0.9.7)
+    sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
     thor (0.19.1)
-    thread_safe (0.3.5)
-    typhoeus (0.8.0)
-      ethon (>= 0.8.0)
-    tzinfo (1.2.2)
-      thread_safe (~> 0.1)
+    typhoeus (1.4.0)
+      ethon (>= 0.9.0)
     uglifier (3.1.4)
       execjs (>= 0.3.0, < 3)
     verbal_expressions (0.1.5)
-    yell (2.0.7)
+    yell (2.2.2)
 
 PLATFORMS
   ruby
@@ -129,16 +140,16 @@ DEPENDENCIES
   algoliasearch-jekyll
   bootstrap-sass
   font-awesome-sass
-  html-proofer
+  html-proofer (>= 3.4.0)
   jekyll
-  jekyll-assets
+  jekyll-assets (>= 2.2.5)
   jekyll-paginate
   jekyll-seo-tag
-  jekyll-sitemap
+  jekyll-sitemap (>= 0.12.0)
   jekyll-tagging
   rails-assets-jquery!
   sass
   uglifier
 
 BUNDLED WITH
-   1.14.0
+   1.17.3