In test_test_command_install_requirements, uninstall setuptools to avoid...

In test_test_command_install_requirements, uninstall setuptools to avoid getting some other version in the environment.

setuptools/tests/test_virtualenv.py

@@ -179,6 +179,8 @@ def test_test_command_install_requirements(virtualenv, tmpdir):
     # Ensure pip/wheel packages are installed.
     virtualenv.run(
         "python -c \"__import__('pkg_resources').require(['pip', 'wheel'])\"")
+    # uninstall setuptools so that 'setup.py develop' works
+    virtualenv.run("python -m pip uninstall -y setuptools")
     _check_test_command_install_requirements(virtualenv, tmpdir)