# A directory of names and phone numbers
class Phonebook
  attr_accessor :data

  def initialize()
    self.data = {}
  end

  # Add a contact to this phone book
  # @param name [String] The name of the contact
  # @param number [String] The phone number of the contact
  def add(name, number)
    data[name] = number
  end
end

Add simple Phonebook data structure
Add simple Phonebook data structure

We are going to be trying to search through a list of contacts (which I
am calling a Phonebook for ease of discussion). We are going to store
these in some form; for now, the simplest possible answer is a hash
mapping Names to Numbers.

For the time being, we are going to consider phone numbers as strings;
this way we can accept arbitrary formatting (until we know better what
expectations Twilio has).
