remove old implements

[maito1201]

I think testrocket is really interesting idea.
But there is some legacy code snippets.
It seems to be left behind in the flow of improvement.

1. remove useless retun value

def _show(r); (TestRocket.out || STDERR) << r + "\n"; r end
That variable "r" was used when testrocket had been started to invent.
But it`s logic is changed, return value is not used now.

2. remove Proc.send

Proc.send :include, TestRocket
now refine and using works enough.
We don't have to load TestRocket module using send method.

[zenspider]

did you run the tests after removing that "useless" return value?