Include a proper license header in source files

[hegjon]

It would make it easier to redistribute python-libnacl in Fedora[1] if each source file contains a license header. None of the source code files contains a license header. Can you update the source files with license header and confirm that all the files are licensed ASL 2.0?

Check https://bugzilla.redhat.com/show_bug.cgi?id=1399833#c3 and for details.

[1] https://fedoraproject.org/wiki/Packaging:LicensingGuidelines?rd=Packaging/LicensingGuidelines#License_Clarification

[thatch45]

Yes, as stated in clause 5 of the Apache license all files contributed to this project inherit the Apache Licence unless explicitly stated otherwise.