Added symbol & string identity tests.

koans/about_strings.rb

@@ -182,4 +182,12 @@ EOS
     words = ["Now", "is", "the", "time"]
     assert_equal __, words.join(" ")
   end
+
+  def test_strings_are_not_unique_objects
+    a = "a string"
+    b = "a string"
+
+    assert_equal __, a           == b
+    assert_equal __, a.object_id == b.object_id
+  end
 end

koans/about_symbols.rb

@@ -19,8 +19,8 @@ class AboutSymbols < EdgeCase::Koan
     symbol1 = :a_symbol
     symbol2 = :a_symbol
 
-    assert symbol1.equal?(__)
-    assert_equal __, symbol2.object_id
+    assert_equal __, symbol1           == symbol2
+    assert_equal __, symbol1.object_id == symbol2.object_id
   end
 
   def test_method_names_become_symbols