Remove explicit requirement on rubygems.

It's better to not force the use of a package manager. Better to add it
to the global RUBYOPT if needed. Also, this fixes a dependency issue
when using the .deb package (rubygems1.9.1 is not required, and should
not be).

lib/foreman/process.rb

@@ -1,5 +1,4 @@
 require "foreman"
-require "rubygems"
 
 class Foreman::Process
 

spec/spec_helper.rb

@@ -1,5 +1,3 @@
-require "rubygems"
-
 require "simplecov"
 SimpleCov.start do
   add_filter "/spec/"