Cannot tests locally because codecov is expecting token

I'm trying to run some tests locally. Following the CONTRIBUTING.rst, this are my steps to reproduce:

Go to https://gitpod.io/#https://github.com/spotify/luigi
$ pip install tox
$ tox -e py27-core test/contrib/postgres_test.py

Expected output: Something like here.

Actual output:

$ tox -e py27-core test/contrib/postgres_test.py
py27-core create: /workspace/luigi/.tox/py27-core
py27-core installdeps: mock<2.0, moto==1.3.6, HTTPretty==0.8.10, nose<2.0, docker>=2.1.0, unittest2<2.0, boto<3.0, boto3>=1.4.4, pyhive[presto]==0.6.1, s3transfer==0.1.13, sqlalchemy<2.0, elasticsearch<2.0.0, psutil<4.0, enum34>1.1.0, mysql-connector-python>=8.0.12, avro, google-compute-engine, coverage>=4.1,<4.2, codecov>=1.4.0, requests>=2.20.0,<3.0, pygments, hypothesis[datetime]<4.0.0, selenium==3.0.2, pymongo==3.4.0, toml<2.0.0, responses<1.0.0, azure-storage, datadog==0.22.0, prometheus-client==0.5.0
py27-core develop-inst: /workspace/luigi
py27-core installed: DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 is no longer maintained. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
py27-core run-test-pre: PYTHONHASHSEED='2378711962'
py27-core run-test: commands[0] | python --version
Python 2.7.17
py27-core run-test: commands[1] | coverage run test/runtests.py -v '--ignore-files=(^\.|^_|^setup\.py$)' test/contrib/postgres_test.py
/workspace/luigi/luigi/__init__.py:78: DeprecationWarning: 
        Autoloading range tasks by default has been deprecated and will be removed in a future version.
        To get the behavior now add an option to luigi.cfg:

          [core]
            autoload_range: false

        Alternately set the option to true to continue with existing behaviour and suppress this warning.

  warnings.warn(warning_message, DeprecationWarning)

----------------------------------------------------------------------
Ran 0 tests in 0.000s

OK
py27-core run-test: commands[2] | coverage combine
py27-core run-test: commands[3] | codecov -e TOXENV

      _____          _
     / ____|        | |
    | |     ___   __| | ___  ___ _____   __
    | |    / _ \ / _  |/ _ \/ __/ _ \ \ / /
    | |___| (_) | (_| |  __/ (_| (_) \ V /
     \_____\___/ \____|\___|\___\___/ \_/
                                    v2.0.22

==> Detecting CI provider
  -> Got branch from git/hg
  -> Got sha from git/hg
==> Preparing upload
Error: Missing repository upload token

Tip: See all example repositories: https://github.com/codecov?query=example
Support channels:
  Email:   hello@codecov.io
  IRC:     #codecov
  Gitter:  https://gitter.im/codecov/support
  Twitter: @codecov

_______________________________________________________________________________________________ summary _______________________________________________________________________________________________
  py27-core: commands succeeded
  congratulations :)

Is this a known bug? How can I run these tests locally?

I would be very thankful for your help in order to efficiently proceed with #2934. :-)

spotify / luigi

Cannot tests locally because codecov is expecting token #2936