use os.homedir() rather than platform-dependent ENV vars
use os.homedir() rather than platform-dependent ENV vars

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