Configuring Go2Pins to be called everywhere

Calling Go2Pins with -blackbox-fn wasn't handled correctly before. By using go modules, we are now able to handles packages creation and using everywhere, especially outside the go2pins directory.
The problem was that we needed to specify our go2pins module path everytime, and in the case that the output directory was created outside the go2pins directory, it would have generated a problem.

We go from this:

import "gitlab.lrde.epita.fr/spot/go2pins/output/blackbox"

to this:

import "output/blackbox" // output is the output directory name

More infos about go modules can be find here.

• boilerplate/Makefile, main.go, tools/blackbox.go : Modified.