Implement/test LOLWUT command

https://redis.io/commands/lolwut

This is a lot of fun to play with:

```python
>>> from redis import Redis
>>> redis = Redis()
>>> print(redis.lolwut(5, 6, 7, 8).decode('utf-8'))
⣴⣶⣶⣶⣶⡆
⣿⣿⣿⣿⣿⡇
⠹⡿⠟⣿⡿⠃
⠀⠀⠀⠀⠀⠀
Georg Nees - schotter, plotter on paper, 1968. Redis ver. 6.0.10

>>> print(redis.lolwut(5, 6, 7, 8).decode('utf-8'))
⢰⣶⣶⣶⣶⡆
⢿⣿⣿⣿⣿⠁
⠸⡿⢿⠿⡿⠃
⠀⠀⠀⠀⠀⠀
Georg Nees - schotter, plotter on paper, 1968. Redis ver. 6.0.10

>>> print(redis.lolwut(5, 6, 7, 8).decode('utf-8'))
⢰⣶⣶⣶⣶⡆
⣸⣿⣿⣻⣿⡅
⠿⡿⠻⠿⠿⠁
⠀⠀⠀⠀⠀⠀
Georg Nees - schotter, plotter on paper, 1968. Redis ver. 6.0.10

>>>
```

Author: brainix

redis/client.py

@@ -1438,6 +1438,13 @@ def ping(self):
         "Ping the Redis server"
         return self.execute_command('PING')
 
+    def lolwut(self, *version_numbers):
+        "Get the Redis version and a piece of generative computer art"
+        if version_numbers:
+            return self.execute_command('LOLWUT VERSION', *version_numbers)
+        else:
+            return self.execute_command('LOLWUT')
+
     def save(self):
         """
         Tell the Redis server to save its data to disk,

tests/test_commands.py

@@ -447,6 +447,13 @@ def test_object(self, r):
     def test_ping(self, r):
         assert r.ping()
 
+    def test_lolwut(self, r):
+        lolwut = r.lolwut().decode('utf-8')
+        assert 'Redis ver.' in lolwut
+
+        lolwut = r.lolwut(5, 6, 7, 8).decode('utf-8')
+        assert 'Redis ver.' in lolwut
+
     def test_slowlog_get(self, r, slowlog):
         assert r.slowlog_reset()
         unicode_string = chr(3456) + 'abcd' + chr(3421)