Made better use of async.series; fixed error handling
Made better use of async.series; fixed error handling

parasgithub/PrairieLearn,tbretl/PrairieLearn,tbretl/PrairieLearn,jakebailey/PrairieLearn,mwest1066/PrairieLearn,tbretl/PrairieLearn,parasgithub/PrairieLearn,tbretl/PrairieLearn,rbessick5/PrairieLearn,rbessick5/PrairieLearn,rbessick5/PrairieLearn,jakebailey/PrairieLearn,mwest1066/PrairieLearn,jakebailey/PrairieLearn,rbessick5/PrairieLearn,jakebailey/PrairieLearn,tbretl/PrairieLearn,mwest1066/PrairieLearn,parasgithub/PrairieLearn,mwest1066/PrairieLearn,parasgithub/PrairieLearn,mwest1066/PrairieLearn,rbessick5/PrairieLearn,parasgithub/PrairieLearn