Depending on your needs,you could probably install gitolite on a 1 gb droplet without any deleterious effect.
Edit (back at a computer): If all you want is a way to have private repositories, gitolite has virtually zero overhead. Installing it is a bit quirky, but once you do, if you’re comfortable using git and editing text files, it’s pretty easy to manage adding new projects and making people be able to access them. (And if you’re not comfortable with git and text files, well. . . . )