In further git genius, update tags before checking them out

Rakefile

@@ -60,7 +60,7 @@ begin
     namespace :rubygems do
       # Rubygems 1.3.5, 1.3.6, and HEAD specs
       rubyopt = ENV["RUBYOPT"]
-      %w(master v1.3.6 v1.3.7 v1.4.0 v1.4.1 v1.5.0).each do |rg|
+      %w(master v1.3.6 v1.3.7 v1.4.2 v1.5.3 v1.6.1).each do |rg|
         desc "Run specs with Rubygems #{rg}"
         RSpec::Core::RakeTask.new(rg) do |t|
           t.rspec_opts = %w(-fs --color)
@@ -72,6 +72,7 @@ begin
             system("git clone git://github.com/rubygems/rubygems.git tmp/rubygems")
           end
           Dir.chdir("tmp/rubygems") do
+            system("git remote update")
             system("git checkout #{rg}")
             system("git pull origin master") if rg == "master"
           end