Add optional pytz dependency

It's reacommended by Django for timezone operations.

Issue #892
Signed-off-by: Michal Čihař <michal@cihar.com>

docs/admin/install.rst

@@ -44,6 +44,8 @@ babel (optional for Android resources support)
     http://babel.pocoo.org/
 Database backend
     Any database supported in Django will work, check their documentation for more details.
+pytz (optional, but recommended by Django)
+    https://pypi.python.org/pypi/pytz/
 hub (optional for sending pull requests to GitHub)
     https://hub.github.com/
 

requirements-optional.txt

@@ -3,6 +3,7 @@ pyuca>=1.1
 pyLibravatar
 pydns; python_version < '3.0'
 py3dns; python_version >= '3.0'
+pytz>=2015.1
 Babel
 chardet
 Mercurial>=2.8; python_version < '3.0'

weblate/requirements.py

@@ -54,6 +54,17 @@ def get_optional_versions():
     '''
     result = []
 
+    name = 'pytz'
+    url = 'https://pypi.python.org/pypi/pytz/'
+    mod = get_version_module('pytz', name, url, True)
+    if mod is not None:
+        result.append((
+            name,
+            url,
+            mod.__version__,
+            None,
+        ))
+
     name = 'pyuca'
     url = 'https://github.com/jtauber/pyuca'
     mod = get_version_module('pyuca', name, url, True)