bundle update rdoc

Author: soutaro

Gemfile.lock

@@ -85,7 +85,7 @@ GEM
     rb-fsevent (0.11.2)
     rb-inotify (0.11.1)
       ffi (~> 1.0)
-    rdoc (6.6.3.1)
+    rdoc (6.9.0)
       psych (>= 4.0.0)
     regexp_parser (2.9.3)
     rspec (3.13.0)