[doc] Update gems

docs/Gemfile.lock

@@ -15,7 +15,7 @@ GEM
     colorator (1.1.0)
     commonmarker (0.17.13)
       ruby-enum (~> 0.5)
-    concurrent-ruby (1.0.5)
+    concurrent-ruby (1.1.3)
     dnsruby (1.61.2)
       addressable (~> 2.5)
     em-websocket (0.5.1)
@@ -81,7 +81,7 @@ GEM
       octokit (~> 4.0)
       public_suffix (~> 2.0)
       typhoeus (~> 1.3)
-    html-pipeline (2.8.4)
+    html-pipeline (2.9.0)
       activesupport (>= 2)
       nokogiri (>= 1.4)
     http_parser.rb (0.6.0)
@@ -185,7 +185,7 @@ GEM
       jekyll-seo-tag (~> 2.0)
     jekyll-titles-from-headings (0.5.1)
       jekyll (~> 3.3)
-    jekyll-watch (2.0.0)
+    jekyll-watch (2.1.2)
       listen (~> 3.0)
     jemoji (0.10.1)
       gemoji (~> 3.0)
@@ -205,11 +205,11 @@ GEM
       jekyll-seo-tag (~> 2.1)
     minitest (5.11.3)
     multipart-post (2.0.0)
-    nokogiri (1.8.4)
+    nokogiri (1.8.5)
       mini_portile2 (~> 2.3.0)
-    octokit (4.12.0)
+    octokit (4.13.0)
       sawyer (~> 0.8.0, >= 0.5.3)
-    pathutil (0.16.1)
+    pathutil (0.16.2)
       forwardable-extended (~> 2.6)
     public_suffix (2.0.5)
     rb-fsevent (0.10.3)
@@ -221,7 +221,7 @@ GEM
     ruby_dep (1.5.0)
     rubyzip (1.2.2)
     safe_yaml (1.0.4)
-    sass (3.6.0)
+    sass (3.7.2)
       sass-listen (~> 4.0.0)
     sass-listen (4.0.0)
       rb-fsevent (~> 0.9, >= 0.9.4)
@@ -232,7 +232,7 @@ GEM
     terminal-table (1.8.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
     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)