[STORE] Added respond_to_missing? to the proxy objects

See:

* http://robots.thoughtbot.com/always-define-respond-to-missing-when-overriding
* http://blog.marc-andre.ca/2010/11/15/methodmissing-politely/

Author: karmi

Diff for: elasticsearch-persistence/lib/elasticsearch/persistence/repository.rb

@@ -8,6 +8,10 @@ def method_missing(method_name, *arguments, &block)
       def respond_to?(method_name, include_private=false)
         gateway.respond_to?(method_name) || super
       end
+
+      def respond_to_missing?(method_name, *)
+        gateway.respond_to?(method_name) || super
+      end
     end
 
     module Repository

Diff for: elasticsearch-persistence/test/unit/repository_module_test.rb

@@ -59,6 +59,11 @@ class DummyRepository
         assert_equal 'snowball', repository.mappings.to_hash[:my_dummy_model][:properties][:title][:analyzer]
       end
 
+      should "correctly delegate to the gateway" do
+        repository = DummyRepository.new
+        assert_instance_of Method, repository.method(:index)
+      end
+
       should "proxy repository methods from the instance to the gateway" do
         class DummyRepository
           include Elasticsearch::Persistence::Repository
@@ -111,6 +116,5 @@ def serialize(document)
     should "configure the index name in the shortcut initializer" do
       assert_equal 'repository', Elasticsearch::Persistence::Repository.new.index_name
     end
-
   end
 end

Diff for: elasticsearch-persistence/test/unit/repository_response_results_test.rb

@@ -63,6 +63,10 @@ class MyDocument; end
       assert_respond_to subject, :each
     end
 
+    should "respond to missing" do
+      assert_instance_of Method, subject.method(:to_a)
+    end
+
     should "yield each object with hit" do
       @shoulda_subject = Repository::Response::Results.new \
         @repository,