Increase pygobject dependency to 2.28.0
Increase pygobject dependency to 2.28.0

This release fixes refcounting bugs that are important for us.

https://bugzilla.gnome.org/show_bug.cgi?id=639597

chergert/libpeas,Distrotech/libpeas,gregier/libpeas,GNOME/libpeas,gregier/libpeas,GNOME/libpeas,Distrotech/libpeas,gregier/libpeas,chergert/libpeas,gregier/libpeas,Distrotech/libpeas,chergert/libpeas