Merge pull request #8 from ThoughtWorksStudios/master

Set content-type when uploading to s3

lib/fluent/plugin/out_s3.rb

@@ -55,7 +55,7 @@ def write(chunk)
     begin
       chunk.write_to(w)
       w.close
-      @bucket.objects[s3path].write(Pathname.new(tmp.path))
+      @bucket.objects[s3path].write(Pathname.new(tmp.path), :content_type => 'application/x-gzip')
     ensure
       w.close rescue nil
     end