Instead of the current structure,refactor everything into service specific modules making it cleaner and easier to work with.
Current structure is :

fedora-change-wrangler
./promote
../convert(issue to user story)
./announce
../mail_list.py(set user story status as well)
./fesco
../pagure_new(creates new issue in pagure)
./accept
../bugzilla_create(creates new bug in bz+issue in pagure + changes user story status in taiga)

As one might notice functionality is divided by the functionality category but all the updation at taiga,bugzilla and pagure is spread out all over the place.

I propose instead dividing it on the basis of service(taiga,pagure,bugzilla) going with the classes approach.
for example
fedora-change-wranger
./taiga
./taiga (contains all auth,conversion,status,custom attr,etc in one place)
./pagure(contains similar approach to taiga in one place)
./bugzilla(Same for bz)
main.py
config.ini

Also as we discussed we can have all the auth here itself in the same place.Code is cleaner,easier to maintain for everyone in the long run.