updated docker images

docker_images/unitgrade-docker/requirements.txt

...ocker/instructor/cs103/__pycache__/report3.cpython-38.pyc

examples/example_docker/instructor/cs103/deploy.py

...example_docker/instructor/cs103/report3_complete_grade.py

examples/example_docker/instructor/cs103/report3_grade.py

...e_docker/instructor/docker/docker_tango_python/Dockerfile

...er/instructor/docker/docker_tango_python/requirements.txt

...mple_docker/instructor/docker/unitgrade-docker/Dockerfile

.../unitgrade-docker/home/cs103/Report3_handin_5_of_10.token

...nstructor/docker/unitgrade-docker/home/cs103/homework1.py

.../instructor/docker/unitgrade-docker/home/cs103/report3.py

...ker/unitgrade-docker/home/cs103/report3_complete_grade.py

...uctor/docker/unitgrade-docker/home/cs103/report3_grade.py

...ocker/instructor/docker/unitgrade-docker/requirements.txt

...ample_docker/students/cs103/Report3_handin_10_of_10.token

...r/students/cs103/__pycache__/report3_grade.cpython-38.pyc

examples/example_docker/students/cs103/report3_grade.py

src/unitgrade_private/docker_helpers.py