RUBY-265 fix OrderedHash#reject!

lib/bson/ordered_hash.rb

@@ -138,6 +138,10 @@ module BSON
         clone.delete_if(&block)
       end
 
+      def reject!(&block)
+        delete_if(&block)
+      end
+
       def clear
         super
         @ordered_keys = []

test/bson/ordered_hash_test.rb

@@ -187,6 +187,11 @@ class OrderedHashTest < Test::Unit::TestCase
     assert !new.keys.include?('z')
   end
 
+  def test_reject_bang
+    @oh.reject! { |k, v| k == 'z' }
+    assert !@ok.keys.include?('z')
+  end
+
   def test_clone
     copy = @oh.clone
     assert copy.keys == @oh.keys