Revert "Politician views barfing if seat_held is not defined"
This was actually a result of an underlying data quality issue,
which has now been fixed... and we actually shouldn't swallow
these errors if it happens again.

This reverts commit e4ca2a3c3ee3e0e54ceb897496e619a3eb686adf.
Revert "Unpopulated district_held causing errors on politician pages"
This was actually a data quality issue.

This reverts commit 77cd7c3feead1b0e6bc0c82acac359811b543db5.
Merge branch 'master' of github.com:sunlightlabs/brisket