add references when test compiling tutorials (#4679)
add references when test compiling tutorials (#4679)


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