Merge pull request #287 from remote-jp/dependabot/bundler/docs/rexml-3.2.8

Bump rexml from 3.2.6 to 3.2.8 in /docs

Author: yasulab

docs/Gemfile.lock

@@ -99,7 +99,8 @@ GEM
     rb-fsevent (0.11.2)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    rexml (3.2.6)
+    rexml (3.2.8)
+      strscan (>= 3.0.9)
     rouge (4.2.0)
     ruby-rc4 (0.1.5)
     safe_yaml (1.0.5)
@@ -115,6 +116,7 @@ GEM
     sass-listen (4.0.0)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
+    strscan (3.1.0)
     support-for (1.0.7)
       sass (~> 3.3)
     terminal-table (3.0.2)