Revert "Update to RubyGems 2.4.5."

This reverts commit 7765f9e.

Author: enebo

lib/ruby/shared/gauntlet_rubygems.rb

@@ -16,7 +16,7 @@
 # rvsh-0.4.5           : No such file or directory - bin/rvsh
 # xen-0.1.2.1          : authors must be Array of Strings
 
-class GemGauntlet < Gauntlet # :nodoc:
+class GemGauntlet < Gauntlet
   def run(name)
     warn name