rjbs/dist-zilla — pull request #135 by book (2012-12-26 16:21:58+00:00)
Title: loosen the constraint on copyright_year

given that the value is inserted in a string, and not used in any
computation involving integers, it seems nice to give authors the
option to declare a range of years is they wish to, such as

copyright_year = 2010-2012