Merge pull request #1430 from gruntwork-io/dependabot/bundler/docs/rexml-3.3.3

Bump rexml from 3.2.5 to 3.3.3 in /docs

Author: ryehowell

docs/Gemfile.lock

@@ -228,7 +228,8 @@ GEM
     rb-inotify (0.10.1)
       ffi (~> 1.0)
     ref (2.0.0)
-    rexml (3.2.5)
+    rexml (3.3.3)
+      strscan
     rouge (3.19.0)
     ruby-enum (0.8.0)
       i18n
@@ -244,6 +245,7 @@ GEM
       faraday (> 0.8, < 2.0)
     simpleidn (0.1.1)
       unf (~> 0.1.4)
+    strscan (3.1.0)
     terminal-table (1.8.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
     therubyracer (0.12.3)