Minor fix to match spec update.

Author: gkellogg

lib/json/ld/flatten.rb

@@ -36,7 +36,7 @@ def create_node_map(element, graph_map,
         raise "Expected hash or array to create_node_map, got #{element.inspect}"
       else
         graph = (graph_map[active_graph] ||= {})
-        subject_node = graph[active_subject]
+        subject_node = !active_subject.is_a?(Hash) && graph[active_subject]
 
         # Transform BNode types
         if element.has_key?('@type')

spec/api_spec.rb

@@ -44,7 +44,7 @@
   end
 
   context "Test Files" do
-    %w(oj json_gem ok_json yajl).map(&:to_sym).each do |adapter|
+    %i(oj json_gem ok_json yajl).each do |adapter|
       context "with MultiJson adapter #{adapter.inspect}" do
         Dir.glob(File.expand_path(File.join(File.dirname(__FILE__), 'test-files/*-input.*'))) do |filename|
           test = File.basename(filename).sub(/-input\..*$/, '')