added test-target for rpython to test translation of json-parser.
added test-target for rpython to test translation of json-parser.

magnusmorton/pycket,pycket/pycket,cderici/pycket,cderici/pycket,magnusmorton/pycket,vishesh/pycket,krono/pycket,cderici/pycket,samth/pycket,krono/pycket,pycket/pycket,krono/pycket,samth/pycket,samth/pycket,vishesh/pycket,pycket/pycket,vishesh/pycket,magnusmorton/pycket