Promoted RemovedInDjango21Warning to error in Django's test suite.

from django.test.utils import get_runner

from django.utils import six

from django.utils._os import upath

from django.utils.deprecation import RemovedInDjango20Warning

from django.utils.deprecation import (

    RemovedInDjango20Warning, RemovedInDjango21Warning,

)

from django.utils.log import DEFAULT_LOGGING

# Make deprecation warnings errors to ensure no usage of deprecated features.

warnings.simplefilter("error", RemovedInDjango20Warning)

warnings.simplefilter("error", RemovedInDjango21Warning)

# Make runtime warning errors to ensure no usage of error prone patterns.

warnings.simplefilter("error", RuntimeWarning)

# Ignore known warnings in test dependencies.