Fix Flakes Errors: openspending/ui/lib/helpers.py
Fix Flakes Errors: openspending/ui/lib/helpers.py

Removing the url or json imports causes tests to fail (even though flakes thinks they are unused).

CivicVision/datahub,johnjohndoe/spendb,nathanhilbert/FPA_Core,nathanhilbert/FPA_Core,nathanhilbert/FPA_Core,openspending/spendb,spendb/spendb,spendb/spendb,USStateDept/FPA_Core,openspending/spendb,USStateDept/FPA_Core,spendb/spendb,openspending/spendb,pudo/spendb,CivicVision/datahub,USStateDept/FPA_Core,pudo/spendb,pudo/spendb,johnjohndoe/spendb,CivicVision/datahub,johnjohndoe/spendb