Refactor python tests to run against python3.9

* Introduce sub-package compat to meet packaging and import requirements
* Update documenation for running tests
* Add requirements.txt to improve IDE support

Signed-off-by: Jhon Honce <jhonce@redhat.com>

test/python/docker/compat/test_system.py

@@ -0,0 +1,68 @@
+import subprocess
+import sys
+import time
+import unittest
+
+from docker import DockerClient
+
+from test.python.docker import Podman, constant
+from test.python.docker.compat import common
+
+
+class TestSystem(unittest.TestCase):
+    podman = None  # initialized podman configuration for tests
+    service = None  # podman service instance
+    topContainerId = ""
+
+    def setUp(self):
+        super().setUp()
+        self.client = DockerClient(base_url="tcp://127.0.0.1:8080", timeout=15)
+
+        TestSystem.podman.restore_image_from_cache(self.client)
+        TestSystem.topContainerId = common.run_top_container(self.client)
+
+    def tearDown(self):
+        common.remove_all_containers(self.client)
+        common.remove_all_images(self.client)
+        self.client.close()
+        return super().tearDown()
+
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        TestSystem.podman = Podman()
+        TestSystem.service = TestSystem.podman.open(
+            "system", "service", "tcp:127.0.0.1:8080", "--time=0"
+        )
+        # give the service some time to be ready...
+        time.sleep(2)
+
+        returncode = TestSystem.service.poll()
+        if returncode is not None:
+            raise subprocess.CalledProcessError(returncode, "podman system service")
+
+    @classmethod
+    def tearDownClass(cls):
+        TestSystem.service.terminate()
+        stdout, stderr = TestSystem.service.communicate(timeout=0.5)
+        if stdout:
+            sys.stdout.write("\nImages Service Stdout:\n" + stdout.decode("utf-8"))
+        if stderr:
+            sys.stderr.write("\nImAges Service Stderr:\n" + stderr.decode("utf-8"))
+
+        TestSystem.podman.tear_down()
+        return super().tearDownClass()
+
+    def test_Info(self):
+        self.assertIsNotNone(self.client.info())
+
+    def test_info_container_details(self):
+        info = self.client.info()
+        self.assertEqual(info["Containers"], 1)
+        self.client.containers.create(image=constant.ALPINE)
+        info = self.client.info()
+        self.assertEqual(info["Containers"], 2)
+
+    def test_version(self):
+        version = self.client.version()
+        self.assertIsNotNone(version["Platform"]["Name"])