Using source repositories as packages sounds like an awful idea. Not only do you have to deal with runtime dependencies, but also compile, test, and other dependencies. What happens if the tags are not numbers? What if a tag you are using is deleted?
Go ask the Erlang community about the issues they have with using GitHub repos as "packages". Here is a discussion about packaging: http://mostlyerlang.com/2015/01/27/054-packages/