Repository: vacanza/python-holidays

Issue:
Duplicate Angola holiday
It seems that there is a duplicate holiday being added in the Angola public holidays.

@jusce17 I see you have made these changes and that you are from Angola. 

What is the difference between `Dia do Herói Nacional` and `Dia dos Heroes Nacional` and why do both of them fall on the same day from 1979. 

Should this have been a name change? Or was it accidentally added?
Add Juneteenth National Holiday



Discussion:

this commit is based on the issue #482 
## Pull Request Test Coverage Report for [Build 1031335428](https://coveralls.io/builds/41375176)

* **2** of **2**   **(100.0%)**  changed or added relevant lines in **1** file are covered.
* No unchanged relevant lines lost coverage.
* Overall coverage increased (+**0.0007%**) to **98.664%**

---



|  Totals | [![Coverage Status](https://coveralls.io/builds/41375176/badge)](https://coveralls.io/builds/41375176) |
| :-- | --: |
| Change from base [Build 1029736853](https://coveralls.io/builds/41357321): |  0.0007% |
| Covered Lines: | 5088 |
| Relevant Lines: | 5091 |

---
##### 💛  - [Coveralls](https://coveralls.io)

Thank you very much! 👍 
Looks like this does the same thing as #474?
@nattofriends, I just checked it now and you are right, I've also seen this problem in other countries, I will be making a PR later this week to fix it 

Resolving patch:
diff --git a/holidays/countries/angola.py b/holidays/countries/angola.py
--- a/holidays/countries/angola.py
+++ b/holidays/countries/angola.py
@@ -57,7 +57,6 @@ def _populate(self, year):
             self[date(year, MAR, 8)] = "Dia Internacional da Mulher"
             self[date(year, APR, 4)] = "Dia da Paz e Reconciliação"
             self[date(year, MAY, 1)] = "Dia Mundial do Trabalho"
-            self[date(year, SEP, 17)] = "Dia dos Heroes Nacional"
             self[date(year, NOV, 2)] = "Dia dos Finados"
             self[date(year, NOV, 11)] = "Dia da Independência"
             self[date(year, DEC, 25)] = "Dia de Natal e da Família"
diff --git a/holidays/countries/united_states.py b/holidays/countries/united_states.py
--- a/holidays/countries/united_states.py
+++ b/holidays/countries/united_states.py
@@ -378,11 +378,6 @@ def _populate(self, year):
                     self[date(year, JUN, 10)] = "Kamehameha Day (Observed)"
                 elif date(year, JUN, 11).weekday() == SUN:
                     self[date(year, JUN, 12)] = "Kamehameha Day (Observed)"
-
-        # Juneteenth National Independence Day
-        if year >= 2021:
-            self[date(year, JUN, 19)] = "Juneteenth National Independence Day"
-
         # Emancipation Day In Texas
         if self.state == "TX" and year >= 1980:
             self[date(year, JUN, 19)] = "Emancipation Day In Texas"


Test patch:
diff --git a/test/countries/test_angola.py b/test/countries/test_angola.py
--- a/test/countries/test_angola.py
+++ b/test/countries/test_angola.py
@@ -46,3 +46,17 @@ def test_not_holiday(self):
         self.assertNotIn("2016-12-28", self.holidays)
         self.assertNotIn("2015-03-02", self.holidays)
         self.assertNotIn("2018-03-23", self.holidays)
+
+    def test_national_hero_day(self):
+
+        for year in range(1980, 1979):
+            self.assertNotIn(date(year, 9, 17), self.holidays)
+        for year in range(1980, 2030):
+            self.assertIn(date(year, 9, 17), self.holidays)
+
+    def test_national_liberation_day(self):
+
+        for year in range(1990, 2018):
+            self.assertNotIn(date(year, 3, 23), self.holidays)
+        for year in range(2019, 2030):
+            self.assertIn(date(year, 3, 23), self.holidays)