Port to Python3

Brief summary of the modifications:

* Use six for compatibility with both Python 2 and 3;
* Replace UserDict.DictMixin with collections.MutableMapping;
* Fix relative imports;
* Use test-requirements.txt for requirements that are common to both Python 2
  and 3, and test-requirements-py{2,3}.txt for version-specific requirements;
* Miscellaneous fixes.
* Use a specific test_db_py3.cfg file for Python 3, that only runs tests on
  sqlite.

Thanks to Victor Stinner who co-wrote this patch.

Change-Id: Ia6dc536c39d274924c21fd5bb619e8e5721e04c4
Co-Authored-By: Victor Stinner <victor.stinner@enovance.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/migrate/tests/versioning/test_api.py b/migrate/tests/versioning/test_api.py
index 4a93c5c..bc4b29d 100644
--- a/migrate/tests/versioning/test_api.py
+++ b/migrate/tests/versioning/test_api.py
@@ -1,6 +1,8 @@
 #!/usr/bin/python
 # -*- coding: utf-8 -*-
 
+import six
+
 from migrate.exceptions import *
 from migrate.versioning import api
 
@@ -12,7 +14,7 @@ from migrate.tests import fixture
 class TestAPI(Pathed):
 
     def test_help(self):
-        self.assertTrue(isinstance(api.help('help'), basestring))
+        self.assertTrue(isinstance(api.help('help'), six.string_types))
         self.assertRaises(UsageError, api.help)
         self.assertRaises(UsageError, api.help, 'foobar')
         self.assertTrue(isinstance(api.help('create'), str))
@@ -48,7 +50,7 @@ class TestAPI(Pathed):
         repo = self.tmp_repos()
         api.create(repo, 'temp')
         api.version_control('sqlite:///', repo)
-        api.version_control('sqlite:///', unicode(repo))
+        api.version_control('sqlite:///', six.text_type(repo))
 
     def test_source(self):
         repo = self.tmp_repos()