Fix typo

python -> Python

Author: changeworld

articles/data-lake-analytics/data-lake-analytics-u-sql-python-extensions.md

@@ -76,7 +76,7 @@ All the standard Python modules are included.
 
 ### Additional Python modules
 
-Besides the standard Python libraries, several commonly used python libraries are included:
+Besides the standard Python libraries, several commonly used Python libraries are included:
 
 * pandas
 * numpy