add some exercises

exercises/done/gecko_02.rb

@@ -0,0 +1,34 @@
+#!/usr/bin/env ruby
+
+class Gecko
+  def initialize(name)
+    @name = name
+    @meals = []
+  end
+
+  def eat(prey, quantity)
+    @meals << [prey, quantity]
+  end
+
+  def display_meals
+    puts "#{@name} a mangé :"
+
+    total = 0
+
+    @meals.each do |prey, quantity|
+      total += quantity
+      puts "- #{quantity} #{prey}"
+    end
+
+    puts
+    puts "Total : #{total} proies"
+  end
+end
+
+delta = Gecko.new("Delta")
+
+delta.eat("dubia", 2)
+delta.eat("ver de farine", 3)
+delta.eat("cloporte", 1)
+
+delta.display_meals