Update syntax highlighting, update allUnique

snippets/is_lower_case.md

@@ -6,12 +6,12 @@ Checks if a string is lower case.
 
 Convert the given string to lower case, using `str.lower()` method and compare it to the original.
 
-```python
+```py
 def is_lower_case(string):
     return string == string.lower()
 ```
 
-```python
+```py
 is_lower_case('abc') # True
 is_lower_case('a3@$') # True
 is_lower_case('Ab4') # False