Fix context data for tax rate finder spec
Fix context data for tax rate finder spec

The spec was accidentally finding an exact tax rate match. The new test
data provides only close matches to choose from.

The naming of variables has been simplified as well.

mkllnk/openfoodnetwork,Matt-Yorkley/openfoodnetwork,lin-d-hop/openfoodnetwork,mkllnk/openfoodnetwork,openfoodfoundation/openfoodnetwork,lin-d-hop/openfoodnetwork,Matt-Yorkley/openfoodnetwork,openfoodfoundation/openfoodnetwork,lin-d-hop/openfoodnetwork,lin-d-hop/openfoodnetwork,Matt-Yorkley/openfoodnetwork,Matt-Yorkley/openfoodnetwork,openfoodfoundation/openfoodnetwork,openfoodfoundation/openfoodnetwork,mkllnk/openfoodnetwork,mkllnk/openfoodnetwork