Adding support for Martini & Goji frameworks - Go

Adding benchmark support for Martini & Goji, two web frameworks for Go.

See: 
   - http://martini.codegangsta.io
   - https://github.com/go-martini/martini
   - https://github.com/zenazn/goji
   - https://goji.io
When `shell=True`, command passed to `subprocess.call` should be str, not list.
So `.rsplit(" ")` should removed.