upgrades to RDoc ~> 3.4 and removes the gem call in root Rakefile (use bundle exec if needed)

Gemfile

@@ -12,7 +12,7 @@ gem "rack", :git => "git://github.com/rack/rack.git"
 
 gem "rake",  ">= 0.8.7"
 gem "mocha", ">= 0.9.8"
-gem "rdoc",  "~> 3.0"
+gem "rdoc",  "~> 3.4"
 gem "horo",  "= 1.0.3"
 
 # for perf tests

Rakefile

 #!/usr/bin/env rake
-gem 'rdoc', '~> 3.0'
-require 'rdoc'
 
 require 'rdoc/task'
 require 'net/http'