Remove unused function

lib/helpers.rb

@@ -24,8 +24,3 @@ end
 def download_button(filename, label='Download CSV data')
   "<a class=button href=#{filename} download=#{filename}>#{label}</a>"
 end
-
-def normalise_decision(d)
-  # https://schemas.opendata.esd.org.uk/PlanningApplications/LocalOpenDataIncentiveSchemePlanningApplicationsSchemaGuidance.pdf
-  
-end