title: Check if array contains string, case insensitive
body: <p>I'm trying to write an application that removes words from a list of words:</p>
  
  <pre><code>puts "Words:"
  text = gets.chomp
  puts "Words to remove:"
  remove = gets.chomp
  words = text.split(" ")
  removes = remove.split(" ")
  words.each do |x| 
      if removes.include.upcase? x.upcase
          print "REMOVED "
      else
          print x, " "
      end
  end
  </code></pre>
  
  <p>How would I make this case insensitive?
  I tried putting <code>.upcase</code> in there but no luck.</p>