Update gems for website (#174)

diff --git a/Gemfile b/Gemfile
index fa27c7c..6f8a225 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,3 @@
 source 'https://rubygems.org'
-gem 'github-pages', '193', group: :jekyll_plugins
+gem 'github-pages', '198', group: :jekyll_plugins
 gem 'therubyracer', '0.12.3'
diff --git a/Gemfile.lock b/Gemfile.lock
index 8009e53..7dd604b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,12 +1,12 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (4.2.10)
+    activesupport (4.2.11.1)
       i18n (~> 0.7)
       minitest (~> 5.1)
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    addressable (2.5.2)
+    addressable (2.6.0)
       public_suffix (>= 2.0.2, < 4.0)
     coffee-script (2.4.1)
       coffee-script-source
@@ -15,38 +15,38 @@
     colorator (1.1.0)
     commonmarker (0.17.13)
       ruby-enum (~> 0.5)
-    concurrent-ruby (1.1.3)
+    concurrent-ruby (1.1.5)
     dnsruby (1.61.2)
       addressable (~> 2.5)
     em-websocket (0.5.1)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
-    ethon (0.11.0)
+    ethon (0.12.0)
       ffi (>= 1.3.0)
     eventmachine (1.2.7)
     execjs (2.7.0)
     faraday (0.15.4)
       multipart-post (>= 1.2, < 3)
-    ffi (1.9.25)
+    ffi (1.11.1)
     forwardable-extended (2.6.0)
-    gemoji (3.0.0)
-    github-pages (193)
-      activesupport (= 4.2.10)
-      github-pages-health-check (= 1.8.1)
-      jekyll (= 3.7.4)
+    gemoji (3.0.1)
+    github-pages (198)
+      activesupport (= 4.2.11.1)
+      github-pages-health-check (= 1.16.1)
+      jekyll (= 3.8.5)
       jekyll-avatar (= 0.6.0)
       jekyll-coffeescript (= 1.1.1)
       jekyll-commonmark-ghpages (= 0.1.5)
       jekyll-default-layout (= 0.1.4)
       jekyll-feed (= 0.11.0)
       jekyll-gist (= 1.5.0)
-      jekyll-github-metadata (= 2.9.4)
+      jekyll-github-metadata (= 2.12.1)
       jekyll-mentions (= 1.4.1)
       jekyll-optional-front-matter (= 0.3.0)
       jekyll-paginate (= 1.1.0)
       jekyll-readme-index (= 0.2.0)
       jekyll-redirect-from (= 0.14.0)
-      jekyll-relative-links (= 0.5.3)
+      jekyll-relative-links (= 0.6.0)
       jekyll-remote-theme (= 0.3.1)
       jekyll-sass-converter (= 1.5.2)
       jekyll-seo-tag (= 2.5.0)
@@ -66,28 +66,28 @@
       jekyll-theme-tactile (= 0.1.1)
       jekyll-theme-time-machine (= 0.1.1)
       jekyll-titles-from-headings (= 0.5.1)
-      jemoji (= 0.10.1)
+      jemoji (= 0.10.2)
       kramdown (= 1.17.0)
       liquid (= 4.0.0)
       listen (= 3.1.5)
       mercenary (~> 0.3)
       minima (= 2.5.0)
-      nokogiri (>= 1.8.2, < 2.0)
+      nokogiri (>= 1.8.5, < 2.0)
       rouge (= 2.2.1)
       terminal-table (~> 1.4)
-    github-pages-health-check (1.8.1)
+    github-pages-health-check (1.16.1)
       addressable (~> 2.3)
       dnsruby (~> 1.60)
       octokit (~> 4.0)
-      public_suffix (~> 2.0)
+      public_suffix (~> 3.0)
       typhoeus (~> 1.3)
-    html-pipeline (2.9.1)
+    html-pipeline (2.11.1)
       activesupport (>= 2)
       nokogiri (>= 1.4)
     http_parser.rb (0.6.0)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
-    jekyll (3.7.4)
+    jekyll (3.8.5)
       addressable (~> 2.4)
       colorator (~> 1.0)
       em-websocket (~> 0.5)
@@ -105,9 +105,9 @@
     jekyll-coffeescript (1.1.1)
       coffee-script (~> 2.2)
       coffee-script-source (~> 1.11.1)
-    jekyll-commonmark (1.2.0)
+    jekyll-commonmark (1.3.1)
       commonmarker (~> 0.14)
-      jekyll (>= 3.0, < 4.0)
+      jekyll (>= 3.7, < 5.0)
     jekyll-commonmark-ghpages (0.1.5)
       commonmarker (~> 0.17.6)
       jekyll-commonmark (~> 1)
@@ -118,8 +118,8 @@
       jekyll (~> 3.3)
     jekyll-gist (1.5.0)
       octokit (~> 4.2)
-    jekyll-github-metadata (2.9.4)
-      jekyll (~> 3.1)
+    jekyll-github-metadata (2.12.1)
+      jekyll (~> 3.4)
       octokit (~> 4.0, != 4.4.0)
     jekyll-mentions (1.4.1)
       html-pipeline (~> 2.3)
@@ -131,7 +131,7 @@
       jekyll (~> 3.0)
     jekyll-redirect-from (0.14.0)
       jekyll (~> 3.3)
-    jekyll-relative-links (0.5.3)
+    jekyll-relative-links (0.6.0)
       jekyll (~> 3.3)
     jekyll-remote-theme (0.3.1)
       jekyll (~> 3.5)
@@ -185,9 +185,9 @@
       jekyll-seo-tag (~> 2.0)
     jekyll-titles-from-headings (0.5.1)
       jekyll (~> 3.3)
-    jekyll-watch (2.1.2)
+    jekyll-watch (2.2.1)
       listen (~> 3.0)
-    jemoji (0.10.1)
+    jemoji (0.10.2)
       gemoji (~> 3.0)
       html-pipeline (~> 2.2)
       jekyll (~> 3.0)
@@ -199,38 +199,38 @@
       rb-inotify (~> 0.9, >= 0.9.7)
       ruby_dep (~> 1.2)
     mercenary (0.3.6)
-    mini_portile2 (2.3.0)
+    mini_portile2 (2.4.0)
     minima (2.5.0)
       jekyll (~> 3.5)
       jekyll-feed (~> 0.9)
       jekyll-seo-tag (~> 2.1)
     minitest (5.11.3)
-    multipart-post (2.0.0)
-    nokogiri (1.8.5)
-      mini_portile2 (~> 2.3.0)
-    octokit (4.13.0)
+    multipart-post (2.1.1)
+    nokogiri (1.10.3)
+      mini_portile2 (~> 2.4.0)
+    octokit (4.14.0)
       sawyer (~> 0.8.0, >= 0.5.3)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
-    public_suffix (2.0.5)
+    public_suffix (3.1.1)
     rb-fsevent (0.10.3)
-    rb-inotify (0.9.10)
-      ffi (>= 0.5.0, < 2)
+    rb-inotify (0.10.0)
+      ffi (~> 1.0)
     ref (2.0.0)
     rouge (2.2.1)
     ruby-enum (0.7.2)
       i18n
     ruby_dep (1.5.0)
-    rubyzip (1.2.2)
-    safe_yaml (1.0.4)
-    sass (3.7.2)
+    rubyzip (1.2.3)
+    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)
-    sawyer (0.8.1)
-      addressable (>= 2.3.5, < 2.6)
-      faraday (~> 0.8, < 1.0)
+    sawyer (0.8.2)
+      addressable (>= 2.3.5)
+      faraday (> 0.8, < 2.0)
     terminal-table (1.8.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
     therubyracer (0.12.3)
@@ -241,14 +241,14 @@
       ethon (>= 0.9.0)
     tzinfo (1.2.5)
       thread_safe (~> 0.1)
-    unicode-display_width (1.4.0)
+    unicode-display_width (1.6.0)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  github-pages (= 193)
+  github-pages (= 198)
   therubyracer (= 0.12.3)
 
 BUNDLED WITH
-   1.17.1
+   1.17.2