run "py" on windows (#2070)
run "py" on windows (#2070)

* run "py" on windows

* python3

* run "py" on windows

* adding logging

* handling file escape issues

switch-education/pxt,playi/pxt,switch-education/pxt,playi/pxt,switchinnovations/pxt,playi/pxt,switch-education/pxt,switchinnovations/pxt,switchinnovations/pxt,playi/pxt,Microsoft/pxt,Microsoft/pxt,Microsoft/pxt,Microsoft/pxt,switch-education/pxt,switch-education/pxt,Microsoft/pxt,switchinnovations/pxt