Redmine repo sync config changed

I've made some changes to the prprocessor and Redmine repo syncing
configuration which should make it easier to add and configure GitHub
repos for Redmine projects.

The list of repos and projects is now centralised in,
which anybody can change via a PR to the repo.

This list contains both the project that the repo should be linked to
(so issues are automatically associated to commits and closed) and the
config for whether to enforce commit messages styles with mandatory
Redmine ticket numbers, plus some other behaviour settings.

Previously the list of synced repos was held in theforeman/redmine and
the list of repos with commit message enforcement in
theforeman/prprocessor. The Redmine hourly sync script now loads the
list of repos/projects from the prprocessor API, syncs the repos and
configures the Redmine projects.

Please let me know if you see any new issues with repo syncing or
prprocessor hooks (e.g. labelling).

ยทยทยท -- Dominic Cleal