Allow more recent polib
Allow more recent polib

There were several useful fixes in polib > 1.0.4
adamjforster/django-rosetta,mbi/django-rosetta,dchoruzy/django-rosetta,mbi/django-rosetta,fladi/django-rosetta,fladi/django-rosetta,BakanovKirill/django-rosetta,BakanovKirill/django-rosetta,BakanovKirill/django-rosetta,dchoruzy/django-rosetta,mbi/django-rosetta,dchoruzy/django-rosetta,fladi/django-rosetta,adamjforster/django-rosetta,mbi/django-rosetta,adamjforster/django-rosetta