Update devDependencies and gems

Gemfile.lock

@@ -4,7 +4,7 @@ GEM
     addressable (2.7.0)
       public_suffix (>= 2.0.2, < 5.0)
     colorator (1.1.0)
-    concurrent-ruby (1.1.5)
+    concurrent-ruby (1.1.6)
     em-websocket (0.5.1)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
@@ -38,13 +38,15 @@ GEM
       jekyll (>= 3.7, < 5.0)
     jekyll-paginate (1.1.0)
     jekyll-redirect-from (0.16.0)
-    jekyll-sass-converter (2.0.1)
+      jekyll (>= 3.3, < 5.0)
+    jekyll-sass-converter (2.1.0)
       sassc (> 2.0.1, < 3.0)
     jekyll-sitemap (1.4.0)
       jekyll (>= 3.7, < 5.0)
     jekyll-watch (2.2.1)
       listen (~> 3.0)
-    kramdown (2.1.0)
+    kramdown (2.2.1)
+      rexml
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
     liquid (4.0.3)
@@ -54,19 +56,20 @@ GEM
     mercenary (0.3.6)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
-    public_suffix (4.0.3)
-    rb-fsevent (0.10.3)
+    public_suffix (4.0.4)
+    rb-fsevent (0.10.4)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    rouge (3.15.0)
+    rexml (3.2.4)
+    rouge (3.18.0)
     safe_yaml (1.0.5)
-    sassc (2.2.1)
+    sassc (2.3.0)
       ffi (~> 1.9)
-    sassc (2.2.1-x64-mingw32)
+    sassc (2.3.0-x64-mingw32)
       ffi (~> 1.9)
     terminal-table (1.8.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
-    unicode-display_width (1.6.1)
+    unicode-display_width (1.7.0)
     wdm (0.1.1)
 
 PLATFORMS