Merge branch 'master' of https://gitlab.cs.ui.ac.id/pmpl/practice-collection/2019/1606833476-practice

Todolist implementation

See merge request !3

# Conflicts:
#   functional_tests.py
#   lists/tests.py
#   lists/views.py
#   superlists/settings.py

# Conflicts:
#   functional_tests.py
#   lists/tests.py
#   lists/views.py
#   superlists/settings.py