Took out LOAD_PATH expansion from demos now that we're gemified

Signed-off-by: pjs <pjs@alum.mit.edu>

demos/MMk.rb

 #!/usr/bin/env ruby
 
-# expand the $LOAD_PATH to find local library modules until such
-# time as SimpleKit gets turned into a Ruby Gem.
-[File.expand_path(File.dirname(__FILE__), '../lib')].each do |new_location|
-  $LOAD_PATH.unshift(new_location) unless $LOAD_PATH.include?(new_location)
-end
+require 'rubygems'
 require 'simplekit'
 
 # Demonstration model of an M/M/k queueing system.  There are k servers

demos/MyModel.rb

 #!/usr/bin/env ruby
 
-# expand the $LOAD_PATH to find local library modules until such
-# time as this gets turned into a Ruby Gem.
-[File.expand_path(File.dirname(__FILE__), '../lib')].each do |new_location|
-  $LOAD_PATH.unshift(new_location) unless $LOAD_PATH.include?(new_location)
-end
+require 'rubygems'
 require 'simplekit'
 
 class MyModel

demos/MyModelArgs.rb

 #!/usr/bin/env ruby
 
-# expand the $LOAD_PATH to find local library modules until such
-# time as this gets turned into a Ruby Gem.
-[File.expand_path(File.dirname(__FILE__), '../lib')].each do |new_location|
-  $LOAD_PATH.unshift(new_location) unless $LOAD_PATH.include?(new_location)
-end
+require 'rubygems'
 require 'simplekit'
 
 class MyModel