Split basic units (#33510)

Split the one monolithic test for basic.py into several files

* Split test_basic.py along categories.
  This is preliminary to get a handle on things.  Eventually we may want
  to further split it so each file is only testing a single function.
* Cleanup unused imports from splitting test_basic.py
* Port atomic_move test to pytest.
  Working on getting rid of need to maintain procenv
* Split a test of symbolic_mode_to_octal to follow unittest best practices
  Each test should only invoke the function under test once
* Port test_argument_spec to pytest.
* Fix suboptions failure

test/units/module_utils/basic/test_get_module_path.py

@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+# (c) 2012-2014, Michael DeHaan <michael.dehaan@gmail.com>
+# (c) 2016 Toshio Kuratomi <tkuratomi@ansible.com>
+# (c) 2017 Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+from units.mock.procenv import ModuleTestCase
+
+from ansible.compat.tests.mock import patch
+from ansible.module_utils.six.moves import builtins
+
+realimport = builtins.__import__
+
+
+class TestGetModulePath(ModuleTestCase):
+    def test_module_utils_basic_get_module_path(self):
+        from ansible.module_utils.basic import get_module_path
+        with patch('os.path.realpath', return_value='/path/to/foo/'):
+            self.assertEqual(get_module_path(), '/path/to/foo')