Skip tests that fail with newer versions of Python.

Patch copied from Gentoo:

https://gitweb.gentoo.org/repo/gentoo.git/tree/dev-python/unittest2/files/unittest2-1.1.0-python3.5-test.patch

diff --git a/unittest2/test/test_loader.py b/unittest2/test/test_loader.py
index 683f662..347eea5 100644
--- a/unittest2/test/test_loader.py
+++ b/unittest2/test/test_loader.py
@@ -509,6 +509,7 @@ class Test_TestLoader(unittest2.TestCase):
     #
     # What happens when an impossible name is given, relative to the provided
     # `module`?
+    @unittest.skipIf(sys.version_info[:2] >= (3, 5), "python 3.5 has problems here")
     def test_loadTestsFromName__relative_malformed_name(self):
         loader = unittest.TestLoader()
 
@@ -811,6 +812,7 @@ class Test_TestLoader(unittest2.TestCase):
     # TestCase or TestSuite instance."
     #
     # What happens when presented with an impossible module name?
+    @unittest.skipIf(sys.version_info[:2] >= (3, 5), "python 3.5 has problems here")
     def test_loadTestsFromNames__malformed_name(self):
         loader = unittest2.TestLoader()
 
@@ -918,6 +920,7 @@ class Test_TestLoader(unittest2.TestCase):
     # "The method optionally resolves name relative to the given module"
     #
     # What happens when presented with an impossible attribute name?
+    @unittest.skipIf(sys.version_info[:2] >= (3, 5), "python 3.5 has problems here")
     def test_loadTestsFromNames__relative_malformed_name(self):
         loader = unittest.TestLoader()
 
diff --git a/unittest2/compatibility.py b/unittest2/compatibility.py
index 9e5f1a5..2d20c19 100644
--- a/unittest2/compatibility.py
+++ b/unittest2/compatibility.py
@@ -140,6 +140,6 @@ except ImportError:
 ###  ChainMap (helper for configparser and string.Template)
 ########################################################################
 
-class ChainMap(collections.MutableMapping):
+class ChainMap(collections.abc.MutableMapping):
     ''' A ChainMap groups multiple dicts (or other mappings) together
     to create a single, updateable view.
d=a59917ea8fd86b35f3ccd6179a0f67be5767712a'>root</a>/<a href='/guix/log/gnu?id=a59917ea8fd86b35f3ccd6179a0f67be5767712a'>gnu</a>/<a href='/guix/log/gnu/installer?id=a59917ea8fd86b35f3ccd6179a0f67be5767712a'>installer</a>/<a href='/guix/log/gnu/installer/utils.scm?id=a59917ea8fd86b35f3ccd6179a0f67be5767712a'>utils.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/installer/utils.scm?id=a59917ea8fd86b35f3ccd6179a0f67be5767712a&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-12-09 17:49:22 +0100'>2022-12-09</span></td><td><a href='/guix/commit/gnu/installer/utils.scm?id=591af24ade1021d91a3e7c62fcc7a8c90f00d4bb'>installer: Print progress bars and such as soon as \r is read.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;https://issues.guix.gnu.org/59922&gt;.

Previously progress bars and related things would be buffered by
'run-external-command-with-line-hooks' until \n is read.

* gnu/installer/utils.scm (run-external-command-with-line-hooks): Use
'read-delimited' rather than 'get-line'.  Pass 'concat as the last
argument.
(%display-line-hook): Remove.
(run-command): Use 'display' instead of '%display-line-hook'.
(%syslog-line-hook): Add "\n" when LINE doesn't end in \n.
(%installer-log-line-hook): Do not add an extra newline.
(installer-log-line): Add an extra newline.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-10-20 10:50:50 +0200'>2022-10-20</span></td><td><a href='/guix/commit/gnu/installer/utils.scm?id=96bb00d20336f43fac2c42662e4b1d300e624738'>installer: Run the "guix system init" command in a PTY.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes: &lt;https://issues.guix.gnu.org/55360&gt;

* gnu/installer/utils.scm (run-external-command-with-handler/tty): New
procedure.
(run-external-command-with-line-hooks, run-command): Add a TTY? argument.
* gnu/installer/final.scm (install-system): Call run-command with TTY?
argument set to #true.
</span></span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2022-09-22 16:00:29 +0200'>2022-09-22</span></td><td><a href='/guix/commit/gnu/installer/utils.scm?id=4814ec284f8a2870e6457c05f414ad31df4e3f57'>installer: Move &lt;secret&gt; to utils and use it for crypt passwords.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/installer/user.scm (&lt;secret&gt;, secret?, make-secret, secret-content): Move
to utils.scm.
* gnu/installer/utils.scm (&lt;secret&gt;, secret?, make-secret, secret-content):
Moved from user.scm.
* gnu/installer/newt/partition.scm (prompt-luks-passwords): Make password a
&lt;secret&gt;.
* gnu/installer/parted.scm (luks-format-and-open): Unwrap secret.

Signed-off-by: Mathieu Othacehe &lt;othacehe@gnu.org&gt;
</span></span></td><td>Josselin Poiret</td></tr>