Test sanity cleanups (#88)

* Test sanity cleanups

Partially addresses #87

- Remove manual lists of tests in favor of loadTestsFromName. This
  mostly gets all test runners running the same number of tests.
- Remove `additional_tests`, which was just duplicating the discovered
  tests. No modern test runner seems to need it.
- Change the two compatibility skip decorators to actually use
  unitetest skips, which helps with the reporting.

* Per @tseaver, drop most test_suite functions.

* Port remaining doctest to unittest.

* Make the odd tests work on all supported python versions

2 files changed, 4 insertions, 23 deletions

diff --git a/src/zope/interface/common/tests/test_idatetime.py b/src/zope/interface/common/tests/test_idatetime.py
index 60f377e..496a5c9 100644
--- a/src/zope/interface/common/tests/test_idatetime.py
+++ b/src/zope/interface/common/tests/test_idatetime.py
@@ -35,13 +35,3 @@ class TestDateTimeInterfaces(unittest.TestCase):
         verifyClass(IDateClass, date)
         verifyClass(IDateTimeClass, datetime)
         verifyClass(ITimeClass, time)
-
-
-def test_suite():
-    suite = unittest.TestSuite()
-    suite.addTest(unittest.makeSuite(TestDateTimeInterfaces))
-    return suite
-
-
-if __name__ == '__main__':
-    unittest.main()
diff --git a/src/zope/interface/common/tests/test_import_interfaces.py b/src/zope/interface/common/tests/test_import_interfaces.py
index 908f05d..fe3766f 100644
--- a/src/zope/interface/common/tests/test_import_interfaces.py
+++ b/src/zope/interface/common/tests/test_import_interfaces.py
@@ -11,19 +11,10 @@
 # FOR A PARTICULAR PURPOSE.
 #
 ##############################################################################
-import doctest
 import unittest
 
-def test_interface_import():
-    """
-    >>> import zope.interface.common.interfaces
-    """
-
-def test_suite():
-    return unittest.TestSuite((
-        doctest.DocTestSuite(),
-        ))
-
-if __name__ == '__main__':
-    unittest.main(defaultTest='test_suite')
+class TestInterfaceImport(unittest.TestCase):
 
+    def test_import(self):
+        import zope.interface.common.interfaces as x
+        self.assertIsNotNone(x)