Pass correct config object to runner tree

lib/mutant/runner/config.rb

@@ -59,7 +59,7 @@ module Mutant
         strategy = self.strategy
         strategy.setup
         @subjects = config.subjects.map do |subject|
-          Subject.run(self, subject)
+          Subject.run(config, subject)
         end
         strategy.teardown
       end

spec/unit/mutant/runner/config/subjects_spec.rb

@@ -32,7 +32,7 @@ describe Mutant::Runner::Config, '#subjects' do
     stub_const('Mutant::Runner::Subject', DummySubjectRunner)
   end
 
-  it { should eql([DummySubjectRunner.new(object, mutation_subject)]) }
+  it { should eql([DummySubjectRunner.new(config, mutation_subject)]) }
 
   it_should_behave_like 'an idempotent method'
 end