added --allow-external twill --allow-unverified twill to travis test-requirements pip install... will go away when we get rid of twill dep
added --allow-external twill --allow-unverified twill to travis test-requirements pip install... will go away when we get rid of twill dep

mark-in/securedrop-prov-upstream,mark-in/securedrop-prov-upstream,mark-in/securedrop-prov-upstream,mark-in/securedrop-prov-upstream