Update Gems to build site for #193
diff --git a/Gemfile b/Gemfile
index d5e21b8..f45751c 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,4 @@
+ruby '>=2.5.1'
 source 'https://rubygems.org'
 gem 'github-pages', group: :jekyll_plugins
 gem 'therubyracer'
diff --git a/Gemfile.lock b/Gemfile.lock
index 8418a63..d744df4 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,11 +1,12 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (4.2.11.1)
-      i18n (~> 0.7)
+    activesupport (6.0.3.2)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
       minitest (~> 5.1)
-      thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
+      zeitwerk (~> 2.2, >= 2.2.2)
     addressable (2.7.0)
       public_suffix (>= 2.0.2, < 5.0)
     coffee-script (2.4.1)
@@ -15,7 +16,7 @@
     colorator (1.1.0)
     commonmarker (0.17.13)
       ruby-enum (~> 0.5)
-    concurrent-ruby (1.1.5)
+    concurrent-ruby (1.1.6)
     dnsruby (1.61.3)
       addressable (~> 2.5)
     em-websocket (0.5.1)
@@ -25,33 +26,32 @@
       ffi (>= 1.3.0)
     eventmachine (1.2.7)
     execjs (2.7.0)
-    faraday (0.17.0)
+    faraday (1.0.1)
       multipart-post (>= 1.2, < 3)
-    ffi (1.11.1)
+    ffi (1.13.1)
     forwardable-extended (2.6.0)
     gemoji (3.0.1)
-    github-pages (200)
-      activesupport (= 4.2.11.1)
+    github-pages (206)
       github-pages-health-check (= 1.16.1)
-      jekyll (= 3.8.5)
-      jekyll-avatar (= 0.6.0)
+      jekyll (= 3.8.7)
+      jekyll-avatar (= 0.7.0)
       jekyll-coffeescript (= 1.1.1)
-      jekyll-commonmark-ghpages (= 0.1.5)
+      jekyll-commonmark-ghpages (= 0.1.6)
       jekyll-default-layout (= 0.1.4)
-      jekyll-feed (= 0.11.0)
+      jekyll-feed (= 0.13.0)
       jekyll-gist (= 1.5.0)
-      jekyll-github-metadata (= 2.12.1)
-      jekyll-mentions (= 1.4.1)
-      jekyll-optional-front-matter (= 0.3.0)
+      jekyll-github-metadata (= 2.13.0)
+      jekyll-mentions (= 1.5.1)
+      jekyll-optional-front-matter (= 0.3.2)
       jekyll-paginate (= 1.1.0)
-      jekyll-readme-index (= 0.2.0)
-      jekyll-redirect-from (= 0.14.0)
-      jekyll-relative-links (= 0.6.0)
-      jekyll-remote-theme (= 0.4.0)
+      jekyll-readme-index (= 0.3.0)
+      jekyll-redirect-from (= 0.15.0)
+      jekyll-relative-links (= 0.6.1)
+      jekyll-remote-theme (= 0.4.1)
       jekyll-sass-converter (= 1.5.2)
-      jekyll-seo-tag (= 2.5.0)
-      jekyll-sitemap (= 1.2.0)
-      jekyll-swiss (= 0.4.0)
+      jekyll-seo-tag (= 2.6.1)
+      jekyll-sitemap (= 1.4.0)
+      jekyll-swiss (= 1.0.0)
       jekyll-theme-architect (= 0.1.1)
       jekyll-theme-cayman (= 0.1.1)
       jekyll-theme-dinky (= 0.1.1)
@@ -61,19 +61,18 @@
       jekyll-theme-midnight (= 0.1.1)
       jekyll-theme-minimal (= 0.1.1)
       jekyll-theme-modernist (= 0.1.1)
-      jekyll-theme-primer (= 0.5.3)
+      jekyll-theme-primer (= 0.5.4)
       jekyll-theme-slate (= 0.1.1)
       jekyll-theme-tactile (= 0.1.1)
       jekyll-theme-time-machine (= 0.1.1)
-      jekyll-titles-from-headings (= 0.5.1)
-      jemoji (= 0.10.2)
+      jekyll-titles-from-headings (= 0.5.3)
+      jemoji (= 0.11.1)
       kramdown (= 1.17.0)
-      liquid (= 4.0.0)
-      listen (= 3.1.5)
+      liquid (= 4.0.3)
       mercenary (~> 0.3)
-      minima (= 2.5.0)
+      minima (= 2.5.1)
       nokogiri (>= 1.10.4, < 2.0)
-      rouge (= 2.2.1)
+      rouge (= 3.19.0)
       terminal-table (~> 1.4)
     github-pages-health-check (1.16.1)
       addressable (~> 2.3)
@@ -81,13 +80,13 @@
       octokit (~> 4.0)
       public_suffix (~> 3.0)
       typhoeus (~> 1.3)
-    html-pipeline (2.12.0)
+    html-pipeline (2.13.0)
       activesupport (>= 2)
       nokogiri (>= 1.4)
     http_parser.rb (0.6.0)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
-    jekyll (3.8.5)
+    jekyll (3.8.7)
       addressable (~> 2.4)
       colorator (~> 1.0)
       em-websocket (~> 0.5)
@@ -100,50 +99,50 @@
       pathutil (~> 0.9)
       rouge (>= 1.7, < 4)
       safe_yaml (~> 1.0)
-    jekyll-avatar (0.6.0)
-      jekyll (~> 3.0)
+    jekyll-avatar (0.7.0)
+      jekyll (>= 3.0, < 5.0)
     jekyll-coffeescript (1.1.1)
       coffee-script (~> 2.2)
       coffee-script-source (~> 1.11.1)
     jekyll-commonmark (1.3.1)
       commonmarker (~> 0.14)
       jekyll (>= 3.7, < 5.0)
-    jekyll-commonmark-ghpages (0.1.5)
+    jekyll-commonmark-ghpages (0.1.6)
       commonmarker (~> 0.17.6)
-      jekyll-commonmark (~> 1)
-      rouge (~> 2)
+      jekyll-commonmark (~> 1.2)
+      rouge (>= 2.0, < 4.0)
     jekyll-default-layout (0.1.4)
       jekyll (~> 3.0)
-    jekyll-feed (0.11.0)
-      jekyll (~> 3.3)
+    jekyll-feed (0.13.0)
+      jekyll (>= 3.7, < 5.0)
     jekyll-gist (1.5.0)
       octokit (~> 4.2)
-    jekyll-github-metadata (2.12.1)
-      jekyll (~> 3.4)
+    jekyll-github-metadata (2.13.0)
+      jekyll (>= 3.4, < 5.0)
       octokit (~> 4.0, != 4.4.0)
-    jekyll-mentions (1.4.1)
+    jekyll-mentions (1.5.1)
       html-pipeline (~> 2.3)
-      jekyll (~> 3.0)
-    jekyll-optional-front-matter (0.3.0)
-      jekyll (~> 3.0)
+      jekyll (>= 3.7, < 5.0)
+    jekyll-optional-front-matter (0.3.2)
+      jekyll (>= 3.0, < 5.0)
     jekyll-paginate (1.1.0)
-    jekyll-readme-index (0.2.0)
-      jekyll (~> 3.0)
-    jekyll-redirect-from (0.14.0)
-      jekyll (~> 3.3)
-    jekyll-relative-links (0.6.0)
-      jekyll (~> 3.3)
-    jekyll-remote-theme (0.4.0)
+    jekyll-readme-index (0.3.0)
+      jekyll (>= 3.0, < 5.0)
+    jekyll-redirect-from (0.15.0)
+      jekyll (>= 3.3, < 5.0)
+    jekyll-relative-links (0.6.1)
+      jekyll (>= 3.3, < 5.0)
+    jekyll-remote-theme (0.4.1)
       addressable (~> 2.0)
-      jekyll (~> 3.5)
-      rubyzip (>= 1.2.1, < 3.0)
+      jekyll (>= 3.5, < 5.0)
+      rubyzip (>= 1.3.0)
     jekyll-sass-converter (1.5.2)
       sass (~> 3.4)
-    jekyll-seo-tag (2.5.0)
-      jekyll (~> 3.3)
-    jekyll-sitemap (1.2.0)
-      jekyll (~> 3.3)
-    jekyll-swiss (0.4.0)
+    jekyll-seo-tag (2.6.1)
+      jekyll (>= 3.3, < 5.0)
+    jekyll-sitemap (1.4.0)
+      jekyll (>= 3.7, < 5.0)
+    jekyll-swiss (1.0.0)
     jekyll-theme-architect (0.1.1)
       jekyll (~> 3.5)
       jekyll-seo-tag (~> 2.0)
@@ -171,8 +170,8 @@
     jekyll-theme-modernist (0.1.1)
       jekyll (~> 3.5)
       jekyll-seo-tag (~> 2.0)
-    jekyll-theme-primer (0.5.3)
-      jekyll (~> 3.5)
+    jekyll-theme-primer (0.5.4)
+      jekyll (> 3.5, < 5.0)
       jekyll-github-metadata (~> 2.9)
       jekyll-seo-tag (~> 2.0)
     jekyll-theme-slate (0.1.1)
@@ -184,45 +183,44 @@
     jekyll-theme-time-machine (0.1.1)
       jekyll (~> 3.5)
       jekyll-seo-tag (~> 2.0)
-    jekyll-titles-from-headings (0.5.1)
-      jekyll (~> 3.3)
+    jekyll-titles-from-headings (0.5.3)
+      jekyll (>= 3.3, < 5.0)
     jekyll-watch (2.2.1)
       listen (~> 3.0)
-    jemoji (0.10.2)
+    jemoji (0.11.1)
       gemoji (~> 3.0)
       html-pipeline (~> 2.2)
-      jekyll (~> 3.0)
+      jekyll (>= 3.0, < 5.0)
     kramdown (1.17.0)
     libv8 (3.16.14.19)
-    liquid (4.0.0)
-    listen (3.1.5)
-      rb-fsevent (~> 0.9, >= 0.9.4)
-      rb-inotify (~> 0.9, >= 0.9.7)
-      ruby_dep (~> 1.2)
+    liquid (4.0.3)
+    listen (3.2.1)
+      rb-fsevent (~> 0.10, >= 0.10.3)
+      rb-inotify (~> 0.9, >= 0.9.10)
     mercenary (0.3.6)
     mini_portile2 (2.4.0)
-    minima (2.5.0)
-      jekyll (~> 3.5)
+    minima (2.5.1)
+      jekyll (>= 3.5, < 5.0)
       jekyll-feed (~> 0.9)
       jekyll-seo-tag (~> 2.1)
-    minitest (5.12.2)
+    minitest (5.14.1)
     multipart-post (2.1.1)
-    nokogiri (1.10.8)
+    nokogiri (1.10.10)
       mini_portile2 (~> 2.4.0)
-    octokit (4.14.0)
+    octokit (4.18.0)
+      faraday (>= 0.9)
       sawyer (~> 0.8.0, >= 0.5.3)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
     public_suffix (3.1.1)
-    rb-fsevent (0.10.3)
-    rb-inotify (0.10.0)
+    rb-fsevent (0.10.4)
+    rb-inotify (0.10.1)
       ffi (~> 1.0)
     ref (2.0.0)
-    rouge (2.2.1)
-    ruby-enum (0.7.2)
+    rouge (3.19.0)
+    ruby-enum (0.8.0)
       i18n
-    ruby_dep (1.5.0)
-    rubyzip (2.0.0)
+    rubyzip (2.3.0)
     safe_yaml (1.0.5)
     sass (3.7.4)
       sass-listen (~> 4.0.0)
@@ -238,11 +236,12 @@
       libv8 (~> 3.16.14.15)
       ref
     thread_safe (0.3.6)
-    typhoeus (1.3.1)
+    typhoeus (1.4.0)
       ethon (>= 0.9.0)
-    tzinfo (1.2.5)
+    tzinfo (1.2.7)
       thread_safe (~> 0.1)
-    unicode-display_width (1.6.0)
+    unicode-display_width (1.7.0)
+    zeitwerk (2.4.0)
 
 PLATFORMS
   ruby
@@ -251,5 +250,8 @@
   github-pages
   therubyracer
 
+RUBY VERSION
+   ruby 2.7.1p83
+
 BUNDLED WITH
-   1.17.2
+   2.1.4