Fixed validate_obama_primary_candidacy_2012
Fixed validate_obama_primary_candidacy_2012

As a result of the changes made for
https://github.com/openelections/core/issues/91, the abbreviation
for the Democratic part is 'D', so the heuristics for this
validator needed to change.

cathydeng/openelections-core,cathydeng/openelections-core,datamade/openelections-core,openelections/openelections-core,datamade/openelections-core,openelections/openelections-core