tox fail with py2.7

[waketzheng]

Traceback (most recent call last):
  File "setup.py", line 65, in <module>
    test_suite='test.test_all',
  File "/home/vagrant/archive/Flask-WhooshAlchemyPlus/.tox/py27/local/lib/python2.7/site-packages/setuptools/__init__.py", line 145, in setup
    return distutils.core.setup(**attrs)
  File "/usr/lib/python2.7/distutils/core.py", line 151, in setup
    dist.run_commands()
  File "/usr/lib/python2.7/distutils/dist.py", line 953, in run_commands
    self.run_command(cmd)
  File "/usr/lib/python2.7/distutils/dist.py", line 972, in run_command
    cmd_obj.run()
  File "/home/vagrant/archive/Flask-WhooshAlchemyPlus/.tox/py27/local/lib/python2.7/site-packages/setuptools/command/test.py", line 228, in run
    self.run_tests()
  File "/home/vagrant/archive/Flask-WhooshAlchemyPlus/.tox/py27/local/lib/python2.7/site-packages/setuptools/command/test.py", line 250, in run_tests
    exit=False,
  File "/usr/lib/python2.7/unittest/main.py", line 94, in __init__
    self.parseArgs(argv)
  File "/usr/lib/python2.7/unittest/main.py", line 149, in parseArgs
    self.createTests()
  File "/usr/lib/python2.7/unittest/main.py", line 158, in createTests
    self.module)
  File "/usr/lib/python2.7/unittest/loader.py", line 130, in loadTestsFromNames
    suites = [self.loadTestsFromName(name, module) for name in names]
  File "/usr/lib/python2.7/unittest/loader.py", line 100, in loadTestsFromName
    parent, obj = obj, getattr(obj, part)
AttributeError: 'module' object has no attribute 'test_all'
ERROR: InvocationError: '/home/vagrant/archive/Flask-WhooshAlchemyPlus/.tox/py27/bin/python setup.py test'
__________________________________________________________________________ summary ___________________________________________________________________________
ERROR:   py27: commands failed

pip freeze:

blinker==1.4
Click==7.0
Flask==1.0.2
Flask-SQLAlchemy==2.3.2
itsdangerous==1.1.0
Jinja2==2.10
MarkupSafe==1.1.1
SQLAlchemy==1.3.1
Werkzeug==0.15.1
Whoosh==2.7.4