Basic compatibility with Python 2.6

- list extra requirements needed on Python 2.6
- provide extra requirements file for pip on Python 2.6
- use requirements-2.6.txt for Python 2.6 on Travis
- try using unittest2 if unittest module does not work

See issue #258

.travis.yml

@@ -11,7 +11,7 @@ before_install:
 install: 
   - pip install --use-mirrors Django==$DJANGO_VERSION
   - pip install --use-mirrors -r requirements.txt
-  - if [[ $TRAVIS_PYTHON_VERSION == '2.6' ]]; then pip install --use-mirrors  importlib ; fi
+  - if [[ $TRAVIS_PYTHON_VERSION == '2.6' ]]; then pip install -r requirements-2.6.txt ; fi
 # Environment setup
   - export VIRT_ROOT=/home/travis/virtualenv/python$TRAVIS_PYTHON_VERSION
   - export PKG_CONFIG_PATH=$VIRT_ROOT/lib/pkgconfig

docs/install.rst

@@ -33,6 +33,14 @@ PyICU (optional for proper sorting of strings)
 Database backend
     Any database supported in Django will work, check their documentation for more details.
 
+If you want to run Weblate with Python 2.6, you should also install following
+modules:
+
+importlib
+    https://pypi.python.org/pypi/importlib
+unittest2
+    https://pypi.python.org/pypi/unittest2
+
 Requirements on Debian or Ubuntu
 ++++++++++++++++++++++++++++++++
 

requirements-2.6.txt

+importlib>=1.0.0
+unittest2>=0.5.0

trans/tests/machine.py

@@ -21,7 +21,10 @@
 from django.test import TestCase
 from trans.tests.views import ViewTestCase
 from trans.models.unit import Unit
-import unittest
+try:
+    from unittest import skipUnless
+except ImportError:
+    from unittest2 import skipUnless
 from trans.machine.dummy import DummyTranslation
 from trans.machine.glosbe import GlosbeTranslation
 from trans.machine.mymemory import MyMemoryTranslation
@@ -73,7 +76,7 @@ class MachineTranslationTest(TestCase):
         machine = ApertiumTranslation()
         self.assertIsInstance(machine.translate('es', 'world', None), list)
 
-    @unittest.skipUnless(microsoft_translation_supported(),
+    @skipUnless(microsoft_translation_supported(),
                          'missing credentials')
     def test_microsoft(self):
         machine = MicrosoftTranslation()