diff --git a/Gemfile b/Gemfile
index 48f4dd1..e1bdaa7 100644
--- a/Gemfile
+++ b/Gemfile
@@ -26,6 +26,8 @@ group :jekyll_plugins do
   gem 'jekyll-sitemap'
   gem 'jekyll-titles-from-headings'
   gem 'jemoji'
+  gem 'sprockets', '~> 4.0.beta'
+  gem 'uglifier'
 end
 gem 'jekyll-sass-converter'
 # themes
diff --git a/Gemfile.lock b/Gemfile.lock
index 9762e63..131bb0e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,10 +1,10 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (4.2.9)
+    activesupport (5.1.4)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (~> 0.7)
       minitest (~> 5.1)
-      thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
     addressable (2.5.2)
       public_suffix (>= 2.0.2, < 4.0)
@@ -33,7 +33,7 @@ GEM
     fastimage (2.1.1)
     ffi (1.9.18)
     forwardable-extended (2.6.0)
-    gemoji (3.0.0)
+    gemoji (2.1.0)
     html-pipeline (2.7.1)
       activesupport (>= 2)
       nokogiri (>= 1.4)
@@ -59,17 +59,20 @@ GEM
       pathutil (~> 0.9)
       rouge (>= 1.7, < 3)
       safe_yaml (~> 1.0)
-    jekyll-assets (2.4.0)
-      concurrent-ruby (~> 1.0)
+    jekyll-assets (3.0.5)
+      activesupport (~> 5.0)
+      execjs (~> 2.7)
       extras (~> 0.2)
       fastimage (~> 2.0, >= 1.8)
-      jekyll (~> 3.1, >= 3.0)
-      pathutil (>= 0.8)
-      rack (~> 1.6)
-      sprockets (~> 3.3, < 3.8)
+      jekyll (>= 3.5, < 4.0)
+      jekyll-sanity (~> 1.2)
+      liquid-tag-parser (~> 1.0)
+      nokogiri (~> 1.8)
+      pathutil (~> 0.16)
+      sprockets (>= 3.3, < 4.1.beta)
     jekyll-avatar (0.5.0)
       jekyll (~> 3.0)
-    jekyll-coffeescript (1.0.2)
+    jekyll-coffeescript (1.1.0)
       coffee-script (~> 2.2)
       coffee-script-source (~> 1.11.1)
     jekyll-commonmark (1.1.0)
@@ -83,9 +86,9 @@ GEM
       jekyll (~> 3.0)
     jekyll-feed (0.9.2)
       jekyll (~> 3.3)
-    jekyll-gist (1.4.1)
+    jekyll-gist (1.5.0)
       octokit (~> 4.2)
-    jekyll-github-metadata (2.9.3)
+    jekyll-github-metadata (2.9.4)
       jekyll (~> 3.1)
       octokit (~> 4.0, != 4.4.0)
     jekyll-optional-front-matter (0.3.0)
@@ -93,7 +96,7 @@ GEM
     jekyll-paginate (1.1.0)
     jekyll-readme-index (0.2.0)
       jekyll (~> 3.0)
-    jekyll-redirect-from (0.12.1)
+    jekyll-redirect-from (0.13.0)
       jekyll (~> 3.3)
     jekyll-relative-links (0.5.2)
       jekyll (~> 3.3)
@@ -101,9 +104,11 @@ GEM
       jekyll (~> 3.5)
       rubyzip (>= 1.2.1, < 3.0)
       typhoeus (>= 0.7, < 2.0)
-    jekyll-sass-converter (1.5.0)
+    jekyll-sanity (1.2.0)
+      jekyll (~> 3.1)
+    jekyll-sass-converter (1.5.1)
       sass (~> 3.4)
-    jekyll-seo-tag (2.3.0)
+    jekyll-seo-tag (2.4.0)
       jekyll (~> 3.3)
     jekyll-sitemap (1.1.1)
       jekyll (~> 3.3)
@@ -152,16 +157,19 @@ GEM
       jekyll (~> 3.3)
     jekyll-watch (1.5.1)
       listen (~> 3.0)
-    jemoji (0.8.1)
-      activesupport (~> 4.0, >= 4.2.9)
-      gemoji (~> 3.0)
+    jemoji (0.6.2)
+      gemoji (~> 2.0)
       html-pipeline (~> 2.2)
       jekyll (>= 3.0)
-    kramdown (1.14.0)
+    kramdown (1.16.2)
     liquid (4.0.0)
-    listen (3.0.6)
-      rb-fsevent (>= 0.9.3)
-      rb-inotify (>= 0.9.7)
+    liquid-tag-parser (1.8.0)
+      extras (~> 0.3)
+      liquid (>= 3.0, < 5.0)
+    listen (3.1.5)
+      rb-fsevent (~> 0.9, >= 0.9.4)
+      rb-inotify (~> 0.9, >= 0.9.7)
+      ruby_dep (~> 1.2)
     mercenary (0.3.6)
     mini_portile2 (2.3.0)
     minima (2.1.1)
@@ -170,20 +178,21 @@ GEM
     multipart-post (2.0.0)
     nokogiri (1.8.1)
       mini_portile2 (~> 2.3.0)
-    octokit (4.7.0)
+    octokit (4.8.0)
       sawyer (~> 0.8.0, >= 0.5.3)
     parallel (1.12.1)
     pathutil (0.16.1)
       forwardable-extended (~> 2.6)
     popper_js (1.12.9)
-    public_suffix (2.0.5)
-    rack (1.6.8)
+    public_suffix (3.0.1)
+    rack (2.0.3)
     rb-fsevent (0.10.2)
     rb-inotify (0.9.10)
       ffi (>= 0.5.0, < 2)
     rouge (2.2.1)
     ruby-enum (0.7.1)
       i18n
+    ruby_dep (1.5.0)
     rubyzip (1.2.1)
     safe_yaml (1.0.4)
     sass (3.5.4)
@@ -194,7 +203,7 @@ GEM
     sawyer (0.8.1)
       addressable (>= 2.3.5, < 2.6)
       faraday (~> 0.8, < 1.0)
-    sprockets (3.7.1)
+    sprockets (4.0.0.beta6)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
     terminal-table (1.8.0)
@@ -204,6 +213,8 @@ GEM
       ethon (>= 0.8.0)
     tzinfo (1.2.4)
       thread_safe (~> 0.1)
+    uglifier (4.1.0)
+      execjs (>= 0.3.0, < 3)
     unicode-display_width (1.3.0)
     yell (2.0.7)
 
@@ -255,7 +266,9 @@ DEPENDENCIES
   mercenary
   minima
   rouge
+  sprockets (~> 4.0.beta)
   terminal-table
+  uglifier
 
 BUNDLED WITH
    1.16.1