Update Gems

Author: Ari Chivukula

Gemfile.lock

@@ -1,6 +1,6 @@
 GIT
   remote: https://github.com/18F/uswds-jekyll.git
-  revision: 55c37f5bb016e8c9a9ac50f2348579a8c058f73e
+  revision: 8778410fd84841c4b801cb39a21c4cfe8f2cba4d
   specs:
     uswds-jekyll (4.1.0)
       jekyll (~> 3.4)
@@ -24,7 +24,7 @@ GEM
     ethon (0.11.0)
       ffi (>= 1.3.0)
     eventmachine (1.2.7)
-    ffi (1.9.23)
+    ffi (1.9.25)
     forwardable-extended (2.6.0)
     html-proofer (3.9.1)
       activesupport (>= 4.2, < 6.0)
@@ -38,7 +38,7 @@ GEM
     http_parser.rb (0.6.0)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
-    jekyll (3.8.2)
+    jekyll (3.8.3)
       addressable (~> 2.4)
       colorator (~> 1.0)
       em-websocket (~> 0.5)
@@ -55,7 +55,7 @@ GEM
       sass (~> 3.4)
     jekyll-watch (2.0.0)
       listen (~> 3.0)
-    kramdown (1.16.2)
+    kramdown (1.17.0)
     liquid (4.0.0)
     listen (3.1.5)
       rb-fsevent (~> 0.9, >= 0.9.4)