Fix: Not start the performance test project using Nancy

For two reasons, I did not start the performance test project using Nancy.

1. This project name is 'Nancy', and output DLL file name is 'Nancy.dll'. This name is same as DLL name of NancyFx. So it was mistakenly overwrite the file.
2. There included settings of hosting on ASP.NET to Web.config.

And, I was implementing to return a JSON response.