[pitivi] tests: Set local to en_US as this is what is expected

[Thibault Saunier <tsaunier src gnome org>]

commit 23ceaaa1322d45a742ceee783129d6d70638511c
Author: Thibault Saunier <tsaunier igalia com>
Date:   Sun Feb 17 23:22:41 2019 -0300

    tests: Set local to en_US as this is what is expected

 tests/common.py     |  2 ++
 tests/test_utils.py | 14 +++++++-------
 2 files changed, 9 insertions(+), 7 deletions(-)
---
diff --git a/tests/common.py b/tests/common.py
index 68638fce..7f170413 100644
--- a/tests/common.py
+++ b/tests/common.py
@@ -21,6 +21,7 @@ A collection of objects to use for testing
 """
 import contextlib
 import gc
+import locale
 import os
 import shutil
 import sys
@@ -73,6 +74,7 @@ for category in ["Gtk", "Gdk", "GLib-GObject", "GES"]:
 
 detect_leaks = os.environ.get("PITIVI_TEST_DETECT_LEAKS", "0") not in ("0", "")
 os.environ["PITIVI_USER_CACHE_DIR"] = tempfile.mkdtemp(suffix="pitiviTestsuite")
+locale.setlocale(locale.LC_ALL, "en_US")
 
 
 def __create_settings(proxyingStrategy=ProxyingStrategy.NOTHING,
diff --git a/tests/test_utils.py b/tests/test_utils.py
index c53a0a3f..fedd43c7 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -18,7 +18,6 @@
 # Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 # Boston, MA 02110-1301, USA.
 import time
-from unittest import TestCase
 from unittest.mock import Mock
 
 from gi.repository import GLib
@@ -35,13 +34,14 @@ from pitivi.utils.ui import beautify_length
 from pitivi.utils.ui import format_audiochannels
 from pitivi.utils.ui import format_audiorate
 from pitivi.utils.ui import format_framerate_value
+from tests import common
 
 second = Gst.SECOND
 minute = second * 60
 hour = minute * 60
 
 
-class TestBeautifyTime(TestCase):
+class TestBeautifyTime(common.TestCase):
     """Tests time beautifying utility methods."""
 
     def __check_beautify_last_updated_timestamp(self, seconds, expected):
@@ -91,7 +91,7 @@ class TestBeautifyTime(TestCase):
         self.__check_beautify_last_updated_timestamp(60 * 60 * 24 * 365 * 3, "About 3 years ago")
 
 
-class TestFormatFramerateValue(TestCase):
+class TestFormatFramerateValue(common.TestCase):
 
     def __check(self, num, denom, expected):
         stream = Mock(spec=GstPbutils.DiscovererVideoInfo)
@@ -122,7 +122,7 @@ class TestFormatFramerateValue(TestCase):
         self.__check(120, 1, "120")
 
 
-class TestFormatAudiorate(TestCase):
+class TestFormatAudiorate(common.TestCase):
 
     def __check(self, rate, expected):
         stream = Mock(spec=GstPbutils.DiscovererAudioInfo)
@@ -140,7 +140,7 @@ class TestFormatAudiorate(TestCase):
         self.__check(960000, "960 kHz")
 
 
-class TestFormatAudiochannels(TestCase):
+class TestFormatAudiochannels(common.TestCase):
 
     def __check(self, channels, expected):
         stream = Mock(spec=GstPbutils.DiscovererAudioInfo)
@@ -155,7 +155,7 @@ class TestFormatAudiochannels(TestCase):
         self.__check(6, "6 (5.1)")
 
 
-class TestDependencyChecks(TestCase):
+class TestDependencyChecks(common.TestCase):
 
     def testDependencies(self):
         gi_dep = GstDependency("Gst", "1.0", "1.0.0")
@@ -191,7 +191,7 @@ class TestDependencyChecks(TestCase):
         self.assertTrue(classic_dep.satisfied)
 
 
-class TestMiscUtils(TestCase):
+class TestMiscUtils(common.TestCase):
 
     def test_fixate_caps_with_defalt_values(self):
         voaacenc_caps = Gst.Caps.from_string(