ruby: import from oldpackages and update to 2.1.2

This commit imports the old Makefile from old openwrt feeds.
Also, the package was updated to the latest version.

The new version was tested in a VM with no aparent problem.
No patches are needed.

I added myself as maintainer. If possible, I would like to gain
commit access.

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>