RPM packaging - GitHub Action and RPM issues

[bluikko]

I have created a GitHub Action for birdwatcher that builds it for CentOS 7 and packages the RPM. It is at a proof of concept stage and could be improved. For example it uses a CentOS 7 Docker image for build that I baked, so it takes quite a long time to prepare that image every run. The fork is at https://github.com/bluikko/birdwatcher/tree/github-action-rpm

I believe that building birdwatcher RPMs (and Alice-LG Docker images) automatically would be very useful for the users of Alice-LG and birdwatcher.

There were two issues after I tested the resulting RPM:

1. The configuration file /etc/birdwatcher/birdwatcher.conf has execute bits. I am not sure if this is because of my build system - it is my first time using GitHub Actions and fpm. Has anyone else noticed this?
2. There are no systemd unit files even though they exist in install/systemd directory in the repository. I reckon one issue with packaging these is whether the BIRD version is 1 or 2 - so should the IPv6 birdwatcher unit file be included.