autograder checks for CSCI 201
https://cs50.readthedocs.io/projects/check50/en/latest/check_writer/#check-writer
check50 --dev . to create __init__.py. Run from .cs50.yml directory. Include ref soln in directory, then delete before push.
extra check for file exist
@check50.check()
def exists():
"""indoor.py exists"""
check50.exists("indoor.py")