results: Update test expectations: now we're using the short post label
results: Update test expectations: now we're using the short post label

This improves the readability of the feed, we think, and since we're
adding the election data now, the 'Member of Parliament for' is less
useful.

DemocracyClub/yournextrepresentative,DemocracyClub/yournextrepresentative,DemocracyClub/yournextrepresentative