diff --git a/Gemfile.lock b/Gemfile.lock
index 866e234..feeb720 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -4,54 +4,65 @@ GEM
     addressable (2.8.0)
       public_suffix (>= 2.0.2, < 5.0)
     colorator (1.1.0)
-    concurrent-ruby (1.1.5)
-    em-websocket (0.5.1)
+    concurrent-ruby (1.1.9)
+    em-websocket (0.5.2)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
     eventmachine (1.2.7)
-    ffi (1.12.1)
+    ffi (1.15.3)
     forwardable-extended (2.6.0)
     http_parser.rb (0.6.0)
-    i18n (0.9.5)
+    i18n (1.8.10)
       concurrent-ruby (~> 1.0)
-    jekyll (3.8.6)
+    jekyll (4.2.0)
       addressable (~> 2.4)
       colorator (~> 1.0)
       em-websocket (~> 0.5)
-      i18n (~> 0.7)
-      jekyll-sass-converter (~> 1.0)
+      i18n (~> 1.0)
+      jekyll-sass-converter (~> 2.0)
       jekyll-watch (~> 2.0)
-      kramdown (~> 1.14)
+      kramdown (~> 2.3)
+      kramdown-parser-gfm (~> 1.0)
       liquid (~> 4.0)
-      mercenary (~> 0.3.3)
+      mercenary (~> 0.4.0)
       pathutil (~> 0.9)
-      rouge (>= 1.7, < 4)
+      rouge (~> 3.0)
       safe_yaml (~> 1.0)
+      terminal-table (~> 2.0)
     jekyll-redirect-from (0.16.0)
       jekyll (>= 3.3, < 5.0)
-    jekyll-sass-converter (1.5.2)
-      sass (~> 3.4)
+    jekyll-sass-converter (2.1.0)
+      sassc (> 2.0.1, < 3.0)
     jekyll-watch (2.2.1)
       listen (~> 3.0)
-    kramdown (1.17.0)
+    kramdown (2.3.1)
+      rexml
+    kramdown-parser-gfm (1.1.0)
+      kramdown (~> 2.0)
     liquid (4.0.3)
-    listen (3.2.1)
+    listen (3.5.1)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
-    mercenary (0.3.6)
+    mercenary (0.4.0)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
     public_suffix (4.0.6)
-    rb-fsevent (0.10.3)
+    rb-fsevent (0.11.0)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    rouge (3.15.0)
+    rexml (3.2.5)
+    rouge (3.26.0)
     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)
+    sassc (2.4.0)
+      ffi (~> 1.9)
+    terminal-table (2.0.0)
+      unicode-display_width (~> 1.1, >= 1.1.1)
+    unicode-display_width (1.7.0)
 
 PLATFORMS
   ruby