Repository: peopledoc/workalendar (python)

Issue:
Russia - Day of Unity
Day of Unity in Russia is celebrated on Nov, 4 (https://en.wikipedia.org/wiki/Unity_Day_(Russia)), but this code seems to put it on Nov 5.
```
(11, 5, "Day of Unity")
```

If I understand it properly, this line should be changed to
```
(11, 4, "Day of Unity")
```

I'll do it if needed. Should I?

Pull request description:
Fix Russia's Day of Unity date
closes #317

- [x] Tests with a significant number of years to be tested for your calendar.
- [x] Changelog amended with a mention describing your changes.


Patch:
diff --git a/Changelog.md b/Changelog.md
index 52466ce..6435015 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -12,6 +12,7 @@
 
 - Fixed United Kingdom bank holiday for 2002 and 2012 (#315).
 - Fix a small flake8 issue with wrong indentation (#319).
+- Fix Russia "Day of Unity" date, set to November 4th, thx @alexitkes for the bug report (#317).
 
 ## 4.0.0 (2019-01-24)
 
diff --git a/workalendar/europe/russia.py b/workalendar/europe/russia.py
index 1ef2554..a582e2c 100644
--- a/workalendar/europe/russia.py
+++ b/workalendar/europe/russia.py
@@ -18,5 +18,5 @@ class Russia(WesternCalendar):
         (5, 1, "Labour Day"),
         (5, 9, "Victory Day"),
         (6, 12, "National Day"),
-        (11, 5, "Day of Unity"),
+        (11, 4, "Day of Unity"),
     )


Test patch:
diff --git a/workalendar/tests/test_europe.py b/workalendar/tests/test_europe.py
index 36048e3..02f8d6a 100644
--- a/workalendar/tests/test_europe.py
+++ b/workalendar/tests/test_europe.py
@@ -689,7 +689,7 @@ class Russia(GenericCalendarTest):
         self.assertIn(date(2018, 5, 1), holidays)  # Labour Day
         self.assertIn(date(2018, 5, 9), holidays)  # Victory Day
         self.assertIn(date(2018, 6, 12), holidays)  # National Day
-        self.assertIn(date(2018, 11, 5), holidays)  # Day of Unity
+        self.assertIn(date(2018, 11, 4), holidays)  # Day of Unity
 
 
 class UnitedKingdomTest(GenericCalendarTest):