Added tests that RenderEngine.render() uses its attributes.
Added tests that RenderEngine.render() uses its attributes.

beni55/pystache,nitish116/pystache,rismalrv/pystache,charbeljc/pystache,jrnold/pystache,arlenesr28/pystache,jrnold/pystache,rismalrv/pystache,defunkt/pystache,harsh00008/pystache,arlenesr28/pystache,harsh00008/pystache,rismalrv/pystache,charbeljc/pystache,nitish116/pystache,harsh00008/pystache,arlenesr28/pystache,beni55/pystache,nitish116/pystache