fix version hierarchy in readme

and add a test, for good measure

README.md

@@ -157,7 +157,7 @@ If the app checks the alpha channel (`'a'`), it finds `2.0.0a3`.
 Just to be clear: `tufup` assumes a typical linear release history without branching, so
 
 ```none
-0.0 < 0.1a < 0.1b < 0.1rc < 0.1rc0 < 0.1rc1 < 0.1 < ...
+0.0 < 0.1a < 0.1b < 0.1rc < 0.1rc1 < 0.1 < ...
 ```
 
 ## Migrating from other update frameworks

tests/test_client.py

@@ -6,6 +6,7 @@
 import unittest
 from unittest.mock import Mock, patch
 
+import packaging.version
 from requests.auth import HTTPBasicAuth
 import tuf.api.exceptions
 from tuf.ngclient import TargetFile
@@ -213,6 +214,14 @@ def test__apply_updates(self):
         client._apply_updates(install=mock_install, skip_confirmation=True)
         mock_install.assert_called()
 
+    def test_version_comparison(self):
+        # verify assumed version hierarchy
+        v = packaging.version.Version
+        self.assertTrue(
+            v('0.0.0') < v('0.1a') < v('0.1b') < v('0.1rc') < v('0.1rc1') < v('0.1')
+        )
+        self.assertEqual(v('0.1rc'), v('0.1rc0'))
+
 
 class AuthRequestsFetcherTests(unittest.TestCase):
     def setUp(self) -> None:

tests/test_common.py

@@ -8,7 +8,7 @@
 from tufup.common import Patcher, TargetMeta
 
 
-class TestTargetMeta(TempDirTestCase):
+class TargetMetaTests(TempDirTestCase):
     def test_init_whitespace(self):
         for kwargs in [
             dict(target_path='w h i t e s p a c e-1.2.3.tar.gz'),