Added tests to ensure API called with correct params.
Added tests to ensure API called with correct params.

AusDTO/dto-digitalmarketplace-buyer-frontend,mtekel/digitalmarketplace-buyer-frontend,mtekel/digitalmarketplace-buyer-frontend,alphagov/digitalmarketplace-buyer-frontend,alphagov/digitalmarketplace-buyer-frontend,AusDTO/dto-digitalmarketplace-buyer-frontend,alphagov/digitalmarketplace-buyer-frontend,alphagov/digitalmarketplace-buyer-frontend,AusDTO/dto-digitalmarketplace-buyer-frontend,AusDTO/dto-digitalmarketplace-buyer-frontend,mtekel/digitalmarketplace-buyer-frontend,mtekel/digitalmarketplace-buyer-frontend