update dependencies

Gemfile

@@ -1,5 +1,5 @@
 source 'https://rubygems.org'
-gem 'jekyll', '3.8.1'
+gem 'jekyll', '~> 3.8'
 gem 'jekyll-swiss'
 gem 'rake'
 gem 'html-proofer'

Gemfile.lock

@@ -1,37 +1,37 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (5.2.0)
+    activesupport (5.2.2)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
-    addressable (2.5.2)
+    addressable (2.6.0)
       public_suffix (>= 2.0.2, < 4.0)
     colorator (1.1.0)
     colorize (0.8.1)
-    concurrent-ruby (1.0.5)
+    concurrent-ruby (1.1.4)
     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)
-    ffi (1.9.23)
+    ffi (1.10.0)
     forwardable-extended (2.6.0)
-    html-proofer (3.8.0)
+    html-proofer (3.10.2)
       activesupport (>= 4.2, < 6.0)
       addressable (~> 2.3)
       colorize (~> 0.8)
       mercenary (~> 0.3.2)
-      nokogiri (~> 1.8.1)
+      nokogiri (~> 1.9)
       parallel (~> 1.3)
       typhoeus (~> 1.3)
       yell (~> 2.0)
     http_parser.rb (0.6.0)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
-    jekyll (3.8.1)
+    jekyll (3.8.5)
       addressable (~> 2.4)
       colorator (~> 1.0)
       em-websocket (~> 0.5)
@@ -46,38 +46,38 @@ GEM
       safe_yaml (~> 1.0)
     jekyll-sass-converter (1.5.2)
       sass (~> 3.4)
-    jekyll-swiss (0.4.0)
-    jekyll-watch (2.0.0)
+    jekyll-swiss (1.0.0)
+    jekyll-watch (2.1.2)
       listen (~> 3.0)
-    kramdown (1.16.2)
-    liquid (4.0.0)
+    kramdown (1.17.0)
+    liquid (4.0.1)
     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)
+    mini_portile2 (2.4.0)
     minitest (5.11.3)
-    nokogiri (1.8.2)
-      mini_portile2 (~> 2.3.0)
-    parallel (1.12.1)
-    pathutil (0.16.1)
+    nokogiri (1.10.1)
+      mini_portile2 (~> 2.4.0)
+    parallel (1.13.0)
+    pathutil (0.16.2)
       forwardable-extended (~> 2.6)
-    public_suffix (3.0.2)
-    rake (12.3.1)
+    public_suffix (3.0.3)
+    rake (12.3.2)
     rb-fsevent (0.10.3)
-    rb-inotify (0.9.10)
-      ffi (>= 0.5.0, < 2)
-    rouge (3.1.1)
+    rb-inotify (0.10.0)
+      ffi (~> 1.0)
+    rouge (3.3.0)
     ruby_dep (1.5.0)
     safe_yaml (1.0.4)
-    sass (3.5.6)
+    sass (3.7.3)
       sass-listen (~> 4.0.0)
     sass-listen (4.0.0)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
     thread_safe (0.3.6)
-    typhoeus (1.3.0)
+    typhoeus (1.3.1)
       ethon (>= 0.9.0)
     tzinfo (1.2.5)
       thread_safe (~> 0.1)
@@ -88,9 +88,9 @@ PLATFORMS
 
 DEPENDENCIES
   html-proofer
-  jekyll (= 3.8.1)
+  jekyll (~> 3.8)
   jekyll-swiss
   rake
 
 BUNDLED WITH
-   1.16.1
+   1.17.2