reverting drop_snp_name_from_user_snps

I quickly went through the last two commits of this branch and reverted what needed to be:
https://github.com/tsujigiri/snpr/commits/drop_snp_name_from_user_snps

The tests probably need to be fixed, too, but at the moment I have work to do. Maybe I can get to it at lunch or you can look through it.