By KELIN DILLON Following Mexico’s state-owned oil company Petróleos Mexicanos (Pemex) acquisition of the Deer Park refinery in Texas, Moody’s Analytics, one of Big Three financial ratings agencies, downgraded the refinery’s evaluation to “junk” status. Moody’s devalued Deer Park from Ba3 to Baa2, meaning it is “in the lower ranking of its generic category,” with the potential to further downgrade