Package taskotron trigger as RPM
Summary: Add specfile for taskotron trigger. This also moves files around
in a way that is more suitable for packaging. Fixes T93.
Test Plan: Build an rpm from the specfile, install it and run fedmsg-hub.
Reviewers: tflink
CC: tflink
Maniphest Tasks: T93
Differential Revision: https://phab.qadevel.cloud.fedoraproject.org/D24