[rubygems/rubygems] Allow releasing with a rubygems pre version

This condition is too restrictive in my opinion. If a user has a pre
version of rubygems installed, she should be fully responsible for it,
and we shouldn't restrict any functionality.

Also, why is a new prerelease disallowed but an old prelease allowed, or
why is 2.0.0.rc2 explictly whitelisted? I believe this kind of
exceptions are one more reason to actually permit this.

rubygems/rubygems@7f77a77620

lib/rubygems/commands/push_command.rb

@@ -79,25 +79,6 @@ def execute
   def send_gem(name)
     args = [:post, "api/v1/gems"]
 
-    latest_rubygems_version = Gem.latest_rubygems_version
-
-    if latest_rubygems_version < Gem.rubygems_version and
-         Gem.rubygems_version.prerelease? and
-         Gem::Version.new('2.0.0.rc.2') != Gem.rubygems_version
-      alert_error <<-ERROR
-You are using a beta release of RubyGems (#{Gem::VERSION}) which is not
-allowed to push gems.  Please downgrade or upgrade to a release version.
-
-The latest released RubyGems version is #{latest_rubygems_version}
-
-You can upgrade or downgrade to the latest release version with:
-
-  gem update --system=#{latest_rubygems_version}
-
-      ERROR
-      terminate_interaction 1
-    end
-
     gem_data = Gem::Package.new(name)
 
     unless @host