Add rdoc to Gemfile. No erro: no such file to load -- rdoc/task

Author: seban

Gemfile

@@ -3,6 +3,7 @@ source "http://rubygems.org"
 gem "rake"
 gem "json", "~>1.4.0"
 gem "json_pure", "~>1.4.0"
+gem "rdoc"
 
 group :test do
   gem "rr", "~>1.0"

Gemfile.lock

@@ -4,6 +4,8 @@ GEM
     json (1.4.6)
     json_pure (1.4.6)
     rake (0.9.2.2)
+    rdoc (3.11)
+      json (~> 1.4)
     rr (1.0.4)
 
 PLATFORMS
@@ -13,4 +15,5 @@ DEPENDENCIES
   json (~> 1.4.0)
   json_pure (~> 1.4.0)
   rake
+  rdoc
   rr (~> 1.0)