Make sure locale is what we want before/after the tests

The locale is a global state, and it was not properly reset to
whatever it was before the unitttest possibly changed it.
This is now fixed.

Not restoring the locale led to weird issues: depending on
the order chosen by "python -m unittest discover" to run
the unit tests, some tests would apparently randomly fail
due to the locale not being what was expected.

For example, test_period_in_timeperiod_archive would
call mock('posts/1970/ 1月/index.html',...) instead of
expected mock('posts/1970/Jan/index.html',...) and fail.

pelican/tests/test_importer.py

@@ -4,6 +4,7 @@ from __future__ import unicode_literals, print_function
 import os
 import re
 
+import locale
 from pelican.tools.pelican_import import wp2fields, fields2pelican, decode_wp_content, build_header, build_markdown_header, get_attachments, download_attachments
 from pelican.tests.support import (unittest, temporary_folder, mute,
                                    skipIfNoExecutable)
@@ -30,9 +31,14 @@ except ImportError:
 class TestWordpressXmlImporter(unittest.TestCase):
 
     def setUp(self):
+        self.old_locale = locale.setlocale(locale.LC_ALL)
+        locale.setlocale(locale.LC_ALL, str('C'))
         self.posts = list(wp2fields(WORDPRESS_XML_SAMPLE))
         self.custposts = list(wp2fields(WORDPRESS_XML_SAMPLE, True))
 
+    def tearDown(self):
+        locale.setlocale(locale.LC_ALL, self.old_locale)
+
     def test_ignore_empty_posts(self):
         self.assertTrue(self.posts)
         for title, content, fname, date, author, categ, tags, kind, format in self.posts:
@@ -261,8 +267,13 @@ class TestBuildHeader(unittest.TestCase):
 @unittest.skipUnless(BeautifulSoup, 'Needs BeautifulSoup module')
 class TestWordpressXMLAttachements(unittest.TestCase):
     def setUp(self):
+        self.old_locale = locale.setlocale(locale.LC_ALL)
+        locale.setlocale(locale.LC_ALL, str('C'))
         self.attachments = get_attachments(WORDPRESS_XML_SAMPLE)
 
+    def tearDown(self):
+        locale.setlocale(locale.LC_ALL, self.old_locale)
+
     def test_recognise_attachments(self):
         self.assertTrue(self.attachments)
         self.assertTrue(len(self.attachments.keys()) == 3)