remove python 3.7 from tests. 
=====================================================
 ``celery.bin.graph``
=====================================================

.. contents::
    :local:
.. currentmodule:: celery.bin.graph

.. automodule:: celery.bin.graph
    :members:
    :undoc-members:

=====================================================
 ``celery.bin.graph``
=====================================================

.. contents::
    :local:
.. currentmodule:: celery.bin.graph

.. automodule:: celery.bin.graph
    :members:
    :undoc-members:
