Renamed exporter_permit to shipment_export_permit
Added migration to rename trade_exporter_permits to trade_shipment_export_permits. Added sandbox_id to shipments. Updated script to submit shipments to submit export_permits links
Set sandbox_id to NULL after submitting the shipments. Adds index to sandbox_id
Don't add duplicates when adding the trade_shipment_export_permits records
Merge pull request #89 from unepwcmc/moving_export_permits

Moving export permits