Generate a random string

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## Random string generator
This solution generates a string of easily readable characters for activation codes; I didn't want people confusing 8 with B, 1 with I, 0 with O, L with 1, etc.

gistfile1.rb

# Generates a random string from a set of easily readable characters
def generate_activation_code(size = 6)
  charset = %w{ 2 3 4 6 7 9 A C D E F G H J K M N P Q R T V W X Y Z}
  (0...size).map{ charset.to_a[rand(charset.size)] }.join
end