Please include COPYING or LICENSE file

[jonathanunderwood]

Hi, while packaging this up for inclusion in Fedora I noticed that the tarball (from PyPi) and repository don't contain a LICENSE or COPYING. It's good practice to do so so that consumers are left in no doubt as to the license the software is distributed under. Many thanks.

[mrocklin]

Note that he has included the license separately in each source file.