Merge pull request #54 from ruby-rdf/feature/atomic-write

Switch supports? :transaction to :atomic_write

Author: gkellogg

lib/rdf/spec/mutable.rb

@@ -237,7 +237,7 @@
 
         context 'when transactions are supported' do
           it 'updates atomically' do
-            if subject.supports?(:transactions)
+            if subject.mutable? && subject.supports?(:atomic_write)
               contents = subject.statements.to_a
 
               expect { subject.delete_insert(@statements, [nil]) }