Add license headers to all files

[acs]

The GPLv3 header is not included in python souce files in the project. They need to be added.

[vchrombie]

Hi @acs

I would like to help with this. Can I work on this ?

[valeriocos]

sure! thank you @vchrombie . As a reference you can rely on the licenses of other components (https://github.com/chaoss/grimoirelab-perceval/blob/master/perceval/backends/core/github.py#L3).

[vchrombie]

Thanks @valeriocos

I will send a PR, to discuss any more things to add. Also on another note, the copyright information needs to be updated the perceval backend source files too. I meant the year.

[valeriocos]

the copyright and author info should be probably updated for all components. Maybe this task could be automated with some scripts. If you want, we can discuss it in a separated issue, WDYT?

[vchrombie]

the copyright and author info should be probably updated for all components. Maybe this task could be automated with some scripts. If you want, we can discuss it in a separated issue, WDYT?

Okay, I am up for it. Can I open an issue regarding this in the grimoirelab repository as it accounts for all the components?

[valeriocos]

sure! thanks