Makes Rakefile activate rdoc >= 2.5.9
Makes Rakefile activate rdoc >= 2.5.9

Signed-off-by: Xavier Noria <be11b38ca2a8492ea688531e4730d7fc0f6b7beb@hashref.com>

delameko/activeresource,SweeD/activeresource,repinel/activeresource,eileencodes/activeresource,rjordan/activeresource,1776/activeresource,peterjm/activeresource,yui-knk/activeresource,wyattisimo/activeresource,rails/activeresource,Shopify/activeresource,chadzilla2080/activeresource,om-nishu-trantor/activeresource,maclover7/activeresource