expecting <"new"> but rendering with <[]>

[Joy Ganguly]

While running RSpec i am getting this error

     Failure/Error: expect(response).to render_template(:new)
       expecting <"new"> but rendering with <[]>

Here is my code and the error details https://gist.github.com/himadriganguly/e1547a512ff54084932d

I am new to RSpec and trying to learn it. I am also having problem understanding mock and stub in RSpec, which is now allow and double in RSpec 3.0.

Thanks to all in advance.